如何用APA、MLA和芝加哥格式引用PDF

APA 7带DOI的期刊——无PDF标签（Grady et al., 2019）：

Grady, J. S., Her, M., Moreno, G., Perez, C., & Yelinek, J. (2019). Emotions in storybooks: A comparison of storybooks that represent ethnic and racial groups in the United States. Psychology of Popular Media Culture, 8(3), 207–217. https://doi.org/10.1037/ppm0000185

APA 7报告，URL本身就是PDF（Winthrop et al., 2019；Common Reference Examples，2026年3月3日）：

Winthrop, R., Ziegler, L., Handa, R., & Fakoya, F. (2019). How playful learning can help leapfrog progress in education. Center for Universal Education at Brookings. https://www.brookings.edu/wp-content/uploads/2019/04/how_playful_learning_can_help_leapfrog_progress_in_education.pdf

MLA 9来自网站的作品，可选格式注（模板）：

作者. 作品标题. 出版者, 年份. 网站, URL. PDF download.

MLA 9指向文件的直接链接（模板）：

作者. 作品标题. 出版者, 年份, URL.

Chicago 18参考文献，带DOI的期刊PDF（Kwon, 2022）：

Kwon, Hyeyoung. "Inclusion Work: Children of Immigrants Claiming Membership in Everyday Life." American Journal of Sociology 127, no. 6 (2022): 1818–59. https://doi.org/10.1086/720277.

Chicago 18注释，可下载电子书（模板）：

1. 名 姓, 书名 (出版者, 年份), chap. 3, PDF.

APA 7括号引用：

(Grady et al., 2019, p. 210)

Reference formats are based on the document type (e.g., journal article, report), not the retrieval method (e.g., online, in print).

Even if you retrieved a work online, determine what type of document it is. Only cite a work as a webpage or website if no other category fits.

How you access an online work will affect how you document it.

At the end of the entry, you might include “PDF download” in the optional-element slot to make clear to the reader that the URL does not take you directly to an html version of the report.

To cite a book consulted online, include either a URL or the name of the database. For downloadable ebook formats, name the format; if no fixed page numbers are available, cite a section title or a chapter or other number in the note (or simply omit).

Chicago 18注释，点明格式（Roy, Kindle）：

1. Arundhati Roy, The God of Small Things (Random House, 2008), chap. 6, Kindle.

Chicago 18参考文献：

Roy, Arundhati. The God of Small Things. Random House, 2008. Kindle.

Chicago 18 Author-Date参考文献（同一本书）：

Roy, Arundhati. 2008. The God of Small Things. Random House. Kindle.

Chicago 18 Author-Date文内：

(Roy 2008, chap. 6)

若下载的文件是PDF，同一栏位（模板，不是真实图书）：

1. 名 姓, 书名 (出版者, 年份), chap. 6, PDF.

6. Kurland and Lerner, Founder s’ Constitution, chap. 4, doc. 29.

没有折行的可读缩短注释（不是第二条官方字符串）：

6. Kurland and Lerner, Founders’ Constitution, chap. 4, doc. 29.

APA 7，DOI，无PDF标签（Grady et al., 2019）：

Grady, J. S., Her, M., Moreno, G., Perez, C., & Yelinek, J. (2019). Emotions in storybooks: A comparison of storybooks that represent ethnic and racial groups in the United States. Psychology of Popular Media Culture, 8(3), 207–217. https://doi.org/10.1037/ppm0000185

APA 7括号：

(Grady et al., 2019)

APA 7，开放PDF URL，无卷号（Lipscomb, 2021）：

Lipscomb, A. Y. (2021, Winter). Addressing trauma in the college essay writing process. The Journal of College Admission, (249), 30–33. https://www.catholiccollegesonline.org/pdf/national_ccaa_in_the_news_-_nacac_journal_of_college_admission_winter_2021.pdf

Chicago 18注释（Kwon, 2022）：

1. Hyeyoung Kwon, "Inclusion Work: Children of Immigrants Claiming Membership in Everyday Life," American Journal of Sociology 127, no. 6 (2022): 1842–43, https://doi.org/10.1086/720277.

Chicago 18参考文献：

Kwon, Hyeyoung. "Inclusion Work: Children of Immigrants Claiming Membership in Everyday Life." American Journal of Sociology 127, no. 6 (2022): 1818–59. https://doi.org/10.1086/720277.

Chicago 18 Author-Date参考文献（同一篇文章）：

Kwon, Hyeyoung. 2022. "Inclusion Work: Children of Immigrants Claiming Membership in Everyday Life." American Journal of Sociology 127 (6): 1818–59. https://doi.org/10.1086/720277.

Chicago 18 Author-Date文内：

(Kwon 2022, 1842–43)

Chicago 18注释，文章ID代替页码范围（Snyder et al., 2025）：

7. Carl D. Snyder et al., "Extant Life Detection Using Label-Free Video Microscopy in Analog Aquatic Environments," PLOS ONE 20, no. 3 (2025): 9–10, e0318239, https://doi.org/10.1371/journal.pone.0318239.

Chicago 18参考文献（Snyder et al., 2025）：

Snyder, Carl D., Manuel Bedrossian, Casey Barr, et al. "Extant Life Detection Using Label-Free Video Microscopy in Analog Aquatic Environments." PLOS ONE 20, no. 3 (2025): e0318239. https://doi.org/10.1371/journal.pone.0318239.

APA 7参考文献（National Cancer Institute, 2019）：

National Cancer Institute. (2019). Taking time: Support for people with cancer (NIH Publication No. 18-2059). U.S. Department of Health and Human Services, National Institutes of Health. https://www.cancer.gov/publications/patient-education/takingtime.pdf

APA 7括号：

(National Cancer Institute, 2019)

APA 7叙述：

National Cancer Institute (2019)

APA 7个人作者报告，URL为.pdf（Winthrop et al., 2019）：

Winthrop, R., Ziegler, L., Handa, R., & Fakoya, F. (2019). How playful learning can help leapfrog progress in education. Center for Universal Education at Brookings. https://www.brookings.edu/wp-content/uploads/2019/04/how_playful_learning_can_help_leapfrog_progress_in_education.pdf

APA 7团体作者报告，URL不是.pdf路径（WHO, 2025；官方Common Reference Examples字符串）：

World Health Organization. (2025). Global report on neglected tropical diseases. https://iris.who.int/server/api/core/bitstreams/9c4655d8-3671-4503-ae51-4a80bb44d5e0/content

APA Style对自己PDF讲义的自我引用：

American Psychological Association. (2022). Creating an APA Style reference list guide. https://apastyle.apa.org/instructional-aids/creating-reference-list.pdf

Chicago 18注释（Kurland and Lerner）：

2. Philip B. Kurland and Ralph Lerner, eds., The Founders’ Constitution (University of Chicago Press, 1987), chap. 10, doc. 19, https://press-pubs.uchicago.edu/founders/.

Chicago 18参考文献：

Kurland, Philip B., and Ralph Lerner, eds. The Founders’ Constitution. University of Chicago Press, 1987. https://press-pubs.uchicago.edu/founders/.

Chicago 18 Author-Date参考文献（同一作品）：

Kurland, Philip B., and Ralph Lerner, eds. 1987. The Founders’ Constitution. University of Chicago Press. https://press-pubs.uchicago.edu/founders/.

Chicago 18注释（Melville, 1851）：

4. Herman Melville, Moby-Dick; or, The Whale (New York, 1851), 627, https://melville.electroniclibrary.org/moby-dick-side-by-side.

Chicago 18参考文献：

Melville, Herman. Moby-Dick; or, The Whale. New York, 1851. https://melville.electroniclibrary.org/moby-dick-side-by-side.

Chicago 18 Author-Date参考文献（Melville）：

Melville, Herman. 1851. Moby-Dick; or, The Whale. New York. https://melville.electroniclibrary.org/moby-dick-side-by-side.

Let’s say, however, you link to a PDF directly from a bibliography or an e-mail sent by a teacher or colleague. In that case, it is usually sufficient to provide the URL that leads to the PDF as the location of the work and to omit a second container:

Works cited，经MLA网站（Style Center；leftover-MLA-task-force-landing-404）：

Executive summary. Report of the Task Force on Doctoral Study in Modern Language and Literature, Modern Language Association of America, 2014. Modern Language Association, 2017, www.mla.org/Resources/Research/Surveys-Reports-and-Other-Documents/Staffing-Salaries-and-Other-Professional-Issues/Report-of-the-Task-Force-on-Doctoral-Study-in-Modern-Language-and-Literature-2014. PDF download.

Works cited，直接文件URL，可读形式（无折行的Style Center路径）：

Executive summary. Report of the Task Force on Doctoral Study in Modern Language and Literature, Modern Language Association of America, 2014, www.mla.org/content/download/25438/1164362/execsumtaskforcedocstudy.pdf.

Executive summary. Report of the Task Force on Doctoral Study in Modern Language and Literature, Modern Language Association of America, 2014, www.mla.org/content/download/25438/1164362/ execsumtaskforcedocstudy.pdf.

If the journal article does not have a DOI and is from an academic research database, end the reference after the page range (for an explanation of why, see the database information page). The reference in this case is the same as for a print journal article.

Do not include database information in the reference unless the journal article comes from a database that publishes works of limited circulation or original, proprietary content, such as UpToDate.

For works without DOIs from most academic research databases, do not include a URL or database information in the reference because these works are widely available.

带DOI的官方APA数据库信息例子（Hallion et al., 2019）：

Hallion, M., Taylor, A., Roberts, R., & Ashe, M. (2019). Exploring the association between physical activity participation and self-compassion in middle-aged adults. Sport, Exercise, and Performance Psychology, 8(3), 305–316. https://doi.org/10.1037/spy0000150

Chicago 18注释：

2. B. T. Hebert, "The Island of Bolsö: A Study of Norwegian Life," Sociological Review 17, no. 4 (1925): 310, EBSCOhost.

Chicago 18参考文献：

Hebert, B. T. "The Island of Bolsö: A Study of Norwegian Life." Sociological Review 17, no. 4 (1925): 307–13. EBSCOhost.

Chicago 18 Author-Date参考文献：

Hebert, B. T. 1925. "The Island of Bolsö: A Study of Norwegian Life." Sociological Review 17 (4): 307–13. EBSCOhost.

Do not include both a DOI and a URL in a reference entry. If a work has both a DOI and a URL, include only the DOI.

Do not add a period after the DOI or URL.

For articles consulted online, include a URL (preferably one based on a DOI; see CMOS 13.7); alternatively, list the name of the database.

URL为PDF的APA 7信息图（Common Reference Examples §10.14）：

American Psychological Association. (n.d.). Data sharing [Infographic]. https://www.apa.org/pubs/journals/data-sharing-infographic.pdf

APA 7新闻稿——括号点明体裁，不是文件（Common Reference Examples §10.4）：

American Psychological Association. (2024, April 11). People who use willpower alone to achieve goals, resist temptation, deemed more trustworthy [Press release]. https://www.apa.org/news/press/releases/2024/04/people-who-use-willpower

APA 7预印本（Latimier, Peyre, and Ramus, 2020；leftover-psyarxiv-now-osf）：

Latimier, A., Peyre, H., & Ramus, F. (2020). A meta-analytic review of the benefit of spacing out retrieval practice episodes on retention. PsyArXiv. https://psyarxiv.com/kzy7u/

后来的正式期刊——若你读的是文章就引这个（Latimier et al., 2021）：

Latimier, A., Peyre, H., & Ramus, F. (2021). A meta-analytic review of the benefit of spacing out retrieval practice episodes on retention. Educational Psychology Review, 33(3), 959–987. https://doi.org/10.1007/s10648-020-09572-8

据2025年Form 1040 PDF做出（leftover-Form-1040-still-2025），不是官方Style Center样本：

Internal Revenue Service. (2025). Form 1040: U.S. individual income tax return. U.S. Department of the Treasury. https://www.irs.gov/pub/irs-pdf/f1040.pdf

APA 7未刊稿模板：

作者, A. A. (年份). 手稿标题 [Unpublished manuscript]. 院系名称, 大学名称.