How do I cite an IEEE journal article?

Use the periodical template from the IEEE Reference Style Guide for Authors V 3.28.2025, section II.M: initials and surname, the article title in quotation marks, the abbreviated journal title, vol., no. when you have it, pages or an article number, an abbreviated month, the year, and doi: when a DOI exists. The official worked example with a DOI is Chiampi and Zilberti, IEEE Trans. Biomed. Eng., Oct. 2011, doi: 10.1109/TBME.2011.2158315.

How do I cite an IEEE standard?

Start with the title of the standard, then the designation and year: IEEE Criteria for Class IE Electric Systems, IEEE Standard 308, 1969. Cite the revision you used. A later amendment is a different source. Confirm the designation on the IEEE Standards Association site rather than copying a classmate's year.

When does IEEE use et al.?

In the sentence, three or more names become the first surname plus et al. In the reference list, IEEE publications print up to six names; only then does the list collapse to the first author plus et al. That is different from APA 7, which uses et al. in every in-text citation from three authors.

Can I still write [1]–[4] in IEEE?

Not under V 3.28.2025. Section I.A now says reference ranges will not include an en dash and must be written out: [1], [2], [3], [4]. Older 2022 handouts and some BibTeX styles still emit the dash. If your conference template has not caught up, follow the template the organizers shipped.

Do I reuse the same number if I cite a source again?

Yes. The first appearance gets the next unused number; every later mention reuses that number. A new page, equation, or figure is a locator on the same number—[3, eq. (2)] or [3, Fig. 1]—not a new entry. ibid. and op. cit. are not IEEE; the 2025 Guide tells editors to eliminate them and renumber.

Should I cite the arXiv version or the IEEE early-access paper?

Cite the publisher version of record once it exists. Section II.M says that once a paper is in advanced online access at the publisher, you cite that version and not the arXiv version. Use an arXiv identifier only while that is the recoverable form, as in the official Urazhdin 2003 example.

Is IEEE the same as Vancouver or ACM?

No. IEEE uses square brackets on the line, initials before surnames, and IEEE journal abbreviations. Vancouver / ICMJE is the medical numbered family, with different punctuation and often superscripts. ACM conferences use ACM author-date house style. Do not import IEEE brackets into an ACM template or a clinical journal.

How to Cite Engineering Sources in IEEE (Reference Style Guide V 3.28.2025) [2026]

Quick Answer: How to Cite Engineering Sources in IEEE

Number sources in the order they first appear. Cite them on the line as [1], inside the punctuation, and reuse that number every later time. The 2025 Guide forbids joining a run of numbers with an en dash: write [1], [2], [3], [4], not [1]–[4]. The reference list is titled References and follows citation order, not the alphabet. Initials come before the surname. Article and paper titles take quotation marks and sentence-style capitalization. Book and journal titles are italic. Journal titles are abbreviated. IEEE publications list every author up to six names; more than six become the first author plus et al. Entries end with a period, including those that end in a DOI, unless the entry ends in a URL.

Official IEEE engineering samples (V 3.28.2025)

Journal article with DOI (II.M):

[1] M. M. Chiampi and L. L. Zilberti, "Induction of electric field in human bodies moving near MRI: An efficient BEM computational procedure," IEEE Trans. Biomed. Eng., vol. 58, no. 10, pp. 2787–2793, Oct. 2011, doi: 10.1109/TBME.2011.2158315.

Published conference paper (II.C):

[4] A. Amador-Perez and R. A. Rodriguez-Solis, "Analysis of a CPW-fed annular slot ring antenna using DOE," in Proc. IEEE Antennas Propag. Soc. Int. Symp., Jul. 2006, pp. 4301–4304.

IEEE standard (II.P):

[9] IEEE Criteria for Class IE Electric Systems, IEEE Standard 308, 1969.

U.S. patent (II.L):

[11] J. P. Wilkinson, "Nonlinear resonant circuit devices," U.S. Patent 3 624 125, Jul. 16, 1990.

In text (I.A), including the 2025 range rule:

as demonstrated in [2]; later notes reuse [2]. Consecutive sources are [1], [2], [3], [4] — never [1]–[4].

Section I.A is the shortest accurate definition of the in-text mark and of the 2025 range change:

IEEE Reference Style Guide V 3.28.2025, I.A

References need not be cited in the text. When they are, they appear on the line, in square brackets, inside the punctuation.

Official in-text patterns:

According to [1]; as demonstrated in [2]; as shown by Brown [4], [5]; as mentioned earlier [2], [4], [5], [6], [7], [9]; Smith [4] and Brown and Jones [5]; Wood et al. [7]

Three or more names in the sentence:

Use “et al.” when three or more names are given for a reference cited in the text.

2025 range rule:

Reference ranges in text will not include an en dash. All references will be written out. For example, “[1]–[4]” will now be “[1], [2], [3], [4]”.

What this guide covers—and what it does not

Use this page when the hard part is the engineering object: an IEEE Transactions article versus its early-access record, a published conference paper versus a talk that was only presented, an IEEE standard versus a datasheet, a U.S. patent versus a technical report, or an arXiv preprint versus the later journal version. For the venue-first choice between IEEE and APA—including HCI, engineering education, and human-factors courses—use IEEE vs APA or the compact APA vs IEEE table. Nearby numbered styles are not IEEE: Vancouver vs APA covers the medical family, and ACM conferences use ACM house style. If you only need a journal-article walkthrough, see how to cite a journal article in IEEE.

The current IEEE authority is the V 3.28.2025 Reference Style Guide

Departments still say "IEEE style." They mean the IEEE Reference Style Guide for Authors (IEEE Publication Operations, V 3.28.2025, March 2025), plus grammar and house style in the IEEE Editorial Style Manual for Authors (updated 29 July 2024). There is no numbered student handbook the way APA 7 has a Publication Manual. Older course handouts still cite the 12 August 2022 Reference Guide; the 2025 edition is the current citation source. The student-visible change is that consecutive reference numbers are no longer joined with an en dash. The IEEE Author Center is the public start page; IEEE Xplore is where you recover volume, issue, month, and DOI for IEEE Transactions. If the assignment sheet, graduate handbook, or journal author guide names a style, that instruction wins.

Current manuals behind IEEE engineering citations
Question	Answer
Current citation source	IEEE Reference Style Guide for Authors, V 3.28.2025
Grammar and house style	IEEE Editorial Style Manual for Authors (updated 29 July 2024)
Publisher	IEEE Publication Operations
Official start page	IEEE Author Center
In-text system	One numbered system, square brackets on the line
Consecutive numbers	Written out: [1], [2], [3], [4] (no en dash)
End list title	References, numbered [1], [2], [3] in citation order

In-Text Citations

Place the bracketed number on the same line as the text, with a space before the opening bracket. Treat the number grammatically like a footnote marker, or use it as a noun ("as demonstrated in [2]"). Once a source has a number, reuse that number for the rest of the paper. The 2025 Guide prefers listing each number in its own brackets and now forbids joining a run of numbers with an en dash. Do not write (1), a superscript ¹, or [1, 2, 3]—those are other numbered families or a punctuation pattern the Guide does not use.

Pointing at a theorem, equation, figure, or page range stays on the same number. Do not invent a second number for a new page of the same source. The Guide's locator forms in I.B are:

Official locator forms (V 3.28.2025, I.B)

[3, Thm. 1]; [3, Lemma 2]; [3, pp. 5–10]; [3, eq. (2)]; [3, Fig. 1]; [3, Appendix I]; [3, Sect. 4.5]; [3, Ch. 2, pp. 5–10]; [3, Algorithm 5].

Reference-List Mechanics

IEEE hangs the bracketed number in its own column. Initials precede the surname. Do not put commas around Jr., Sr., or III. Month abbreviations take a period except May. Two months for one issue are joined with a slash (Jul./Aug.). If a reference has both a DOI or accessed date and a URL, the 2025 Guide places the DOI or accessed date first, a period, then the URL. Every reference must include at least a year; if no date is available, use (n.d.) in the date slot. The Guide is explicit about author counts and about never bundling two works under one number:

Official IEEE author-count and numbering rules (V 3.28.2025, II)

IEEE publications must list names of all authors, up to six names. If there are more than six names listed, use the primary author’s name followed by “et al.”

Do not combine references. There must be only one reference with each number.

Note that periodical titles of only one word should not be abbreviated, but fully spelled out, e.g., Science and Nature.

Journal Articles

Peer-reviewed articles in IEEE Transactions and other technical journals are the default research source. The periodical template in section II.M is author, quoted article title, abbreviated journal title, vol., no. when you have it, pp. or an article number, abbreviated month, year, and doi: when the work has one. Single-word titles such as Science and Nature stay spelled out. For IEEE Transactions published before 1988, the volume often carried a journal acronym (vol. ED-11). If the issue number or month is missing, look the record up on IEEE Xplore rather than inventing it. When a page range looks like one long number or starts at 1 in a large volume, it may be an article ID—use Art. no. rather than pp.

Official IEEE periodical examples (V 3.28.2025, II.M)

IEEE Transactions with DOI:

Proceedings of the IEEE (May has no period):

[2] W. Rafferty, "Ground antennas in NASA’s deep space telecommunications," Proc. IEEE, vol. 82, no. 5, pp. 636-640, May 1994.

Article number instead of pages:

[3] R. Fardel, M. Nagel, F. Nuesch, T. Lippert, and A. Wokaun, "Fabrication of organic light emitting diode pixels by laser-assisted forward transfer," Appl. Phys. Lett., vol. 91, no. 6, Aug. 2007, Art. no. 061103.

Later article-ID example (2022):

X. Yang, W. Cao, Y. Lu, and Y. Zhou, "Hyperspectral image transformer classification networks," IEEE Trans. Geosci. Remote Sens., vol. 60, 2022, Art. no. 5528715, doi: 10.1109/TGRS.2022.3171551.

Early access (use Date of Publication, keep the DOI):

F. Vatta, A. Soranzo, and F. Babich, "More accurate analysis of sum-product decoding of LDPC codes using a Gaussian approximation," IEEE Commun. Lett., early access, Dec. 11, 2018, doi: 10.1109/LCOMM.2018.2886261.

Accepted but not yet scheduled work uses to be published—never "to appear in." A manuscript that has not been accepted uses submitted for publication. Early-access articles keep the journal title, the words early access, the online-version date when you have it, and the DOI, because the DOI will not change even if the date does.

Conference Papers versus Talks

Conference proceedings are everyday literature in electrical engineering and computer science, not a second-class leftover until the journal version appears. Section II.C splits two situations students mix up. A published proceedings paper uses in plus an abbreviated conference name and must have page numbers. A talk that was only presented uses presented at the and may add a paper number; it is not a proceedings chapter. Abbreviate the conference name with the Guide's list (Proc., Int., Conf., Symp., Annu.) and drop most articles and prepositions:

Official conference-name rule (V 3.28.2025, II.C)

Proceedings of the 1996 Robotics and Automation Conference becomes Proc. 1996 Robot. Automat. Conf.

Official IEEE conference examples (V 3.28.2025, II.C)

Published proceedings:

[4] A. Amador-Perez and R. A. Rodriguez-Solis, "Analysis of a CPW-fed annular slot ring antenna using DOE," in Proc. IEEE Antennas Propag. Soc. Int. Symp., Jul. 2006, pp. 4301–4304.

Proceedings with DOI:

[5] G. Veruggio, "The EURON roboethics roadmap," in Proc. Humanoids ’06: 6th IEEE-RAS Int. Conf. Humanoid Robots, 2006, pp. 612–617, doi: 10.1109/ICHR.2006.321337.

Presented only, not published:

D. Caratelli, M. C. Viganó, G. Toso, and P. Angeletti, "Analytical placement technique for sparse arrays," presented at the 32nd ESA Antenna Workshop, Noordwijk, The Netherlands, Oct. 5–8, 2010.

Books and Book Chapters

IEEE still prints the city, the U.S. state when the publisher is in the United States, the country, and an abbreviated publisher name. Book titles are italic title case. A chapter sits in quotation marks before in and the book title; the editor is Ed. or Eds. after the book title, with a comma before the city in the 2025 examples. Edition statements sit after the title.

Official IEEE book examples (V 3.28.2025, II.B)

Whole book:

[7] B. Klaus and P. Horn, Robot Vision. Cambridge, MA, USA: MIT Press, 1986.

Chapter in an edited book:

L. Stein, "Random patterns," in Computers and You, J. S. Brake, Ed., New York, NY, USA: Wiley, 1994, pp. 55–70.

Standards

IEEE, ANSI, ITU, and NERC documents are ordinary engineering sources, not grey literature you hide. The Guide's standard template in section II.P is the title of the standard, the standard number, the corporate author and location when you have them, and the date. Cite the revision you actually used. A later IEEE Std 802.3 amendment is not interchangeable with an earlier one. The IEEE Standards Association is where you confirm the designation. An online standard adds [Online]. Available: and the URL.

Official IEEE standard examples (V 3.28.2025, II.P)

IEEE standard:

[9] IEEE Criteria for Class IE Electric Systems, IEEE Standard 308, 1969.

ANSI standard:

Letter Symbols for Quantities, ANSI Standard Y10.5-1968.

Online reliability standard:

Frequency Response and Bias, NERC Reliability Standard BAL-003-0.1b, May 2009. [Online]. Available: http://www.nerc.com/files/BAL-003-0_1b.pdf

Patents

Patents document prior art and establish intellectual-property claims. Section II.L wants the inventor, the quoted title, the issuing country, the patent number with spaces the way IEEE prints it, and the issued date. If several dates appear on the face of the patent, use the issued date. The day of the month is not optional decoration:

Official IEEE patent rule and example (V 3.28.2025, II.L)

Retain or request the day of the month when referencing a patent.

U.S. patent:

[11] J. P. Wilkinson, "Nonlinear resonant circuit devices," U.S. Patent 3 624 125, Jul. 16, 1990.

Technical Reports and White Papers

Place the company or laboratory after the author and title, then the report number and date (section II.N). Online reports add [Online]. Available: and a URL; include a year. A vendor white paper is still a report: keep the corporate author, the words White Paper when that is how the document labels itself, and a recoverable URL.

Official IEEE report examples (V 3.28.2025, II.N)

Technical report:

E. E. Reber, R. L. Michell, and C. J. Carter, "Oxygen absorption in the Earth’s atmosphere," Aerospace Corp., Los Angeles, CA, USA, Tech. Rep. TR-0200 (4230-46)-3, Nov. 1988.

Online white paper:

F. Zhao, "Smartphone solutions white paper," Shenzhen, China, Huawei, White Paper, 2012. [Online]. Available: http://www.huawei.com/ilink/en/download/HW_193034

Software, Datasets, and Preprints

IEEE follows the FORCE11 data citation principles and the FORCE11 software citation principles. Cite the version you ran. The software template in section II.O wants author or organization, software name, year or version, publisher or repository, an accessed date when the location can move, and a persistent identifier or URL. Datasets in section II.E need creators, a date, the dataset title with version, the distributor, and a DOI or handle. A preprint in section II.S that later becomes a journal article is not interchangeable with the version of record.

Official IEEE software, dataset, and preprint examples

Software (II.O):

D. W. Arning et al. Mixed Mode–Mixed Level Circuit Simulator. (2011). Ngspice. Accessed: Jan. 11, 2019. [Online]. Available: http://ngspice.sourceforge.net

Dataset (II.E):

S. Ansolabehere, M. Palmer, and A. Lee, January 20, 2014, "Precinct-Level Election Data. V1," distributed by Harvard Election Data Archive, http://hdl.handle.net/1902.1/21919

arXiv preprint (II.S):

S. Urazhdin, N. O. Birge, W. P. Pratt Jr., and J. Bass, "Current-driven magnetic excitations in permalloy-based multilayer nanopillars," 2003, arXiv:0303149.

When the same paper exists as both an arXiv posting and publisher early access, the Guide tells you which one to keep:

Official early-access rule (V 3.28.2025, II.M)

Once an article is in the form of advanced online access at the publisher, cite this version, and not the arXiv version. The online access is the final version of record.

Theses and Dissertations

IEEE distinguishes a master's thesis from a Ph.D. dissertation (section II.Q). The template is quoted title, M.S. thesis or Ph.D. dissertation, abbreviated department, abbreviated university, city, state or country, and year. Omit the state abbreviation when the university name already includes the state (Univ. California, Berkeley). An online thesis adds [Online]. Available: and the repository URL. The Guide says to keep the words thesis and dissertation as the degree-granting institution used them. If the same research later appears as a book or journal article, cite the published version you actually read.

Official IEEE thesis examples (V 3.28.2025, II.Q)

Ph.D. dissertation:

[17] J. O. Williams, "Narrow-band analyzer," Ph.D. dissertation, Dept. Elect. Eng., Harvard Univ., Cambridge, MA, USA, 1993.

M.S. thesis:

N. Kawasaki, "Parametric study of thermal and chemical nonequilibrium nozzle flow," M.S. thesis, Dept. Electron. Eng., Osaka Univ., Osaka, Japan, 1993.

Online M.S. thesis:

D. Schwartz, "Development of a computationally efficient full human body finite element model," M.S. thesis, Virginia Tech – Wake Forest Univ. School of Biomed. Eng. Sci., Winston-Salem, NC, USA, 2015. [Online]. Available: https://wakespace.lib.wfu.edu/bitstream/handle/10339/57119/Schwartz_wfu_0248M_10697.pdf

Handbooks, Datasheets, Manuals, and Websites

A semiconductor databook, a receiving-tube manual, or a vendor antenna catalog is a handbook or manual in IEEE (sections II.F and II.I), not a journal article. Print manuals start with the title, then the edition, company, city, and year. If no date is available, the 2025 Guide puts (n.d.) in the date slot. Websites (section II.T) are the other common failure: IEEE wants an access date and the words [Online]. Available: before the URL. APA 7 does not. Do not paste an IEEE Accessed: clause into an APA entry, and do not drop the access date from an IEEE webpage.

Official IEEE handbook, datasheet, and website examples

Handbook / datasheet (II.F):

Motorola Semiconductor Data Manual, Motorola Semiconductor Products Inc., Phoenix, AZ, USA, 1989.

No date (II style notes):

BAR50 Series Infineon PIN Diode Datasheet. (n.d.). [Online]. Available: http://www.infineon.com

Website (II.T; IEEE prints [Online.] with the period inside the brackets):

J. Smith. "Obama inaugurated as President." CNN.com. Accessed: Feb. 1, 2009. [Online.] Available: http://www.cnn.com/POLITICS/01/21/obama_inaugurated/index.html

Blogs, Lectures, and Online Video

The 2025 Guide added worked forms for blogs (II.A), lecture notes (II.G), and online video (II.K). Use them when the recoverable object is a post, a slide deck, or a YouTube file—not when the same claim later appears as a journal article. A standards-society blog post is still a blog; do not dress it up as a periodical.

Official IEEE blog, lecture, and video examples (V 3.28.2025)

IEEE ComSoc technology blog (II.A):

A. Weissberger, "FCC approves EchoStar/Dish request to extend timeline for its 5G buildout," IEEE ComSoc Technol. Blog, Sep. 23, 2024. [Online]. Available: https://techblog.comsoc.org/2024/09/23/fcc-approves-echostar-dish-request-to-extend-timeline-for-its-5g-buildout/

Lecture slides (II.G):

J. Barney. (2011). Documenting literature [PowerPoint slides]. Available: http://moodle.cotr/english/gill

Online video (II.K):

mtaOnline1, Fazi Mosque, U.K. An Occasionally Accurate History of Australia: Part I. (Oct. 23, 2006). Accessed: Oct. 6, 2010. [Online Video]. Available: http://www.youtube.com/watch?v=IJjNsCVHc34

Why Engineering Citations Are Not Decorative

In engineering, a citation is part of the technical argument. It is how you show which standard a design meets, which algorithm you implemented, which prior art a patent claim sits on, and which measurement setup another lab would need in order to reproduce the result. Safety-critical work inherits that duty: a load rating, a clearance, or a protocol version that cannot be recovered is not a complete method. Citation integrity is therefore professional ethics, not only academic habit—respect for intellectual property, transparency about methods, and a recoverable trail from claim to source.

IEEE versus ACM versus APA in an Engineering Course

IEEE is the default for IEEE journals, IEEE conferences, and most electrical- and computer-engineering reports. It is not automatic for every computing paper. ACM venues use ACM's own author-date house style. HCI, computing-education, and human-factors courses often want APA 7. Clinical or biomedical programs may want Vancouver. "Engineering uses numbers" is not a rule. The venue template wins. If you are still choosing a style, use which citation style should I use or citation styles by discipline.

Stay on this page

You already know the paper is IEEE
You need the journal, conference, standard, or patent template
You are writing an IEEE Transactions or IEEE conference paper
The source list is heavy with IEEE Std documents and patents

Use a comparison page first

The syllabus might still be APA 7
The course is HCI, engineering education, or human factors
The venue is ACM, not IEEE
You need IEEE vs APA before you format a single entry

Failure Modes Students Actually Hit

Adding a source in the middle of a draft. Every later number has to move. A reference manager (Zotero, EndNote, or the IEEEtran BibTeX file on CTAN) is the fix; hand-renumbering is how [7] points at the wrong paper.
Writing `[1]`–`[4]`. The 2025 Guide writes every number out: [1], [2], [3], [4]. Older 2022 handouts and some .bst files still emit the dash.
Writing `[1, 2, 3]`. The Guide's examples keep each number in its own brackets: [1], [2], [3].
*IEEE et al. in the wrong place. In the sentence, three or more names become et al.* In the reference list, IEEE still prints up to six names.
Combining several works under one number. The Editorial Style Manual and the Reference Style Guide both forbid it.
Month punctuation. Jan., Feb., Mar., Apr., Jun., Jul., Aug., Sep., Oct., Nov., and Dec. take a period. May does not.
Treating a DOI like a URL. IEEE writes doi: 10.1109/… and still ends the reference with a period. APA writes https://doi.org/… and does not. See how to use DOIs.
Citing the arXiv version after the paper is in IEEE early access. Keep the publisher version of record.
Citing a talk as if it were a proceedings paper. Use presented at when there are no published pages.
Dropping the day from a patent or inventing a patent number you did not read.
Importing IEEE brackets into an ACM or APA paper because the topic is technical. The venue wins.
Wrong IEEE mark: (1) or a superscript ¹ instead of [1]. Superscripts are a different numbered family.
Inventing an issue number instead of checking IEEE Xplore. The 2025 Guide tells you to research the record when month or issue is missing.

Tools That Keep IEEE Numbers Attached to the Right Paper

IEEE Xplore for official volume, issue, month, and DOI on IEEE publications.
IEEE Author Center and the V 3.28.2025 Reference Style Guide linked above for templates the generator will miss (standards, patents, early access, presented-only talks).
IEEE Reference Preparation Assistant on the Author Center, to check a finished list against IEEE house style.
IEEEtran plus BibTeX or biblatex so inserting a citation does not renumber the list by hand.
Zotero, Mendeley, or JabRef with an IEEE style file, then a human pass on conference abbreviations, the no-en-dash range rule, and standard designations.
ACM Digital Library, Engineering Village (Compendex), and arXiv for computing and preprint literature—then cite the version of record when it exists.

Frequently Asked Questions

How do I cite an IEEE journal article?: Use the periodical template from the IEEE Reference Style Guide for Authors V 3.28.2025, section II.M: initials and surname, the article title in quotation marks, the abbreviated journal title, vol., no. when you have it, pages or an article number, an abbreviated month, the year, and doi: when a DOI exists. The official worked example with a DOI is Chiampi and Zilberti, IEEE Trans. Biomed. Eng., Oct. 2011, doi: 10.1109/TBME.2011.2158315.
How do I cite a conference paper in IEEE?: If the paper was published in proceedings, write in plus the abbreviated conference name and include page numbers (Amador-Perez and Rodriguez-Solis, Proc. IEEE Antennas Propag. Soc. Int. Symp., Jul. 2006, pp. 4301–4304). If the work was only presented, use presented at the, the workshop or meeting name, the city, and the dates. Do not invent page numbers for a talk that was never printed.
How do I cite an IEEE standard?: Start with the title of the standard, then the designation and year: IEEE Criteria for Class IE Electric Systems, IEEE Standard 308, 1969. Cite the revision you used. A later amendment is a different source. Confirm the designation on the IEEE Standards Association site rather than copying a classmate's year.
How do I cite a U.S. patent in IEEE?: Inventor, quoted title, U.S. Patent, the number with IEEE's internal spaces, and the issued day: J. P. Wilkinson, "Nonlinear resonant circuit devices," U.S. Patent 3 624 125, Jul. 16, 1990. Section II.L says to retain or request the day of the month. If several dates appear, use the issued date.
When does IEEE use et al.?: In the sentence, three or more names become the first surname plus et al. In the reference list, IEEE publications print up to six names; only then does the list collapse to the first author plus et al. That is different from APA 7, which uses et al. in every in-text citation from three authors.
Can I still write [1]–[4] in IEEE?: Not under V 3.28.2025. Section I.A now says reference ranges will not include an en dash and must be written out: [1], [2], [3], [4]. Older 2022 handouts and some BibTeX styles still emit the dash. If your conference template has not caught up, follow the template the organizers shipped.
Do I reuse the same number if I cite a source again?: Yes. The first appearance gets the next unused number; every later mention reuses that number. A new page, equation, or figure is a locator on the same number—[3, eq. (2)] or [3, Fig. 1]—not a new entry. ibid. and op. cit. are not IEEE; the 2025 Guide tells editors to eliminate them and renumber.
Should I cite the arXiv version or the IEEE early-access paper?: Cite the publisher version of record once it exists. Section II.M says that once a paper is in advanced online access at the publisher, you cite that version and not the arXiv version. Use an arXiv identifier only while that is the recoverable form, as in the official Urazhdin 2003 example.
Is IEEE the same as Vancouver or ACM?: No. IEEE uses square brackets on the line, initials before surnames, and IEEE journal abbreviations. Vancouver / ICMJE is the medical numbered family, with different punctuation and often superscripts. ACM conferences use ACM author-date house style. Do not import IEEE brackets into an ACM template or a clinical journal.
How do I cite software or a circuit simulator in IEEE?: Cite the version you ran, with enough of a location to recover it. The official software example in section II.O is D. W. Arning et al. Mixed Mode–Mixed Level Circuit Simulator. (2011). Ngspice. Accessed: Jan. 11, 2019. [Online]. Available: http://ngspice.sourceforge.net. Include the version number or release date; "MATLAB" with no version is not a complete reference.

Format the paper in IEEE, then generate the entries

If the venue is IEEE, stay in IEEE for every source. Use the IEEE generator for journal articles and books, then open the V 3.28.2025 Reference Style Guide for standards, patents, early access, and presented-only talks—those are the rows generators miss. If the course might still be APA, decide that first.

IEEE citation generator IEEE vs APA decision guide APA vs IEEE comparison table