Clear, Real-World Examples of Chicago Style Author-Date System

Instead of starting with theory, let’s jump straight into examples of Chicago style author-date system examples you’re likely to need in a real paper. Then we’ll unpack the patterns.

Imagine you’re writing a research paper on public health communication and you use a book, a journal article, and a government website.

Here’s how your in-text citations might look in Chicago author-date style:

• A book with one author: (Rosenberg 2020, 45)
• A journal article with two authors: (Nguyen and Patel 2023, 118)
• A government website with an organization as author: (Centers for Disease Control and Prevention 2024)

And here’s how those same sources look in the reference list:

• Rosenberg, Daniel. 2020. Health Communication in the Digital Age. New York: Oxford University Press.
• Nguyen, Linh, and Priya Patel. 2023. “Social Media and Vaccine Hesitancy among Young Adults.” Journal of Public Health Research 15 (2): 110–130. https://doi.org/10.1234/jphr.2023.5678.
• Centers for Disease Control and Prevention. 2024. “COVID-19 Vaccination: Trends and Coverage.” Last modified March 15, 2024. https://www.cdc.gov/coronavirus/2019-ncov/vaccines.

Those three examples include most of the moving parts you’ll see repeated in other examples of Chicago style author-date system examples: author, year, page (if needed), and then full details in the reference list.

Core pattern: how the author-date system works

Before we get into more specific examples include books, articles, and websites, let’s pin down the basic pattern.

In the Chicago author-date system:

• In-text citations go in parentheses, usually at the end of the sentence, with author’s last name + year and page number if you’re quoting or referring to a specific part.
• The reference list at the end of your paper gives the full details of every source you cited, organized alphabetically by author’s last name.

So the pattern looks like this:

• In-text: (Author Year, page) → for example: (Harvard University 2022, 3)
• Reference list: Author, First Name. Year. Title in Headline Style. Publication details.

Once you see that pattern, the rest of the best examples of Chicago style author-date system are just variations on the same theme.

Book and chapter citations: best examples you’ll actually use

Let’s walk through some examples of Chicago style author-date system examples for books and book chapters, since those show up in almost every research paper.

Single-author book

In-text citation:
You’re paraphrasing an idea from page 72:

Many first-year students struggle most with organizing their research, not with finding sources (Booth 2016, 72).

Reference list entry:

Booth, Wayne C. 2016. The Craft of Research. 4th ed. Chicago: University of Chicago Press.

Two or three authors

In-text citation:

Collaborative note-taking can significantly improve recall during lectures (Graff and Birkenstein 2021, 54).

Reference list entry:

Graff, Gerald, and Cathy Birkenstein. 2021. They Say / I Say: The Moves That Matter in Academic Writing. 5th ed. New York: W. W. Norton.

With three authors, you list all three in the reference list, but in the text you still list all three the first time. Later citations can use et al. if your instructor allows it.

Reference list entry with three authors:

Smith, Jordan, Alicia Flores, and Michael Lee. 2022. College Writing and Research Skills. Boston: Bedford/St. Martin’s.

In-text (first time): (Smith, Flores, and Lee 2022, 101)
In-text (later, if allowed): (Smith et al. 2022, 101)

Chapter in an edited book

Now an example of a chapter in an edited collection, which trips a lot of students up.

In-text citation:

Multilingual classrooms require flexible assessment strategies (Garcia 2020, 89).

Reference list entry:

Garcia, Ofelia. 2020. “Assessing Multilingual Learners in the 21st Century Classroom.” In Rethinking Assessment in Education, edited by Linda Darling-Hammond and Pedro Noguera, 80–102. New York: Teachers College Press.

This is one of the best examples to study because it shows how to handle a chapter author and book editors in the same entry.

Articles and reports: real examples for research-heavy papers

Most research papers lean heavily on journal articles and reports. Here are several examples of Chicago style author-date system examples you can mirror.

Peer-reviewed journal article with DOI

In-text citation:

Students who engage in active learning tend to perform better on conceptual exams (Freeman et al. 2014, 841).

Reference list entry:

Freeman, Scott, Sarah L. Eddy, Miles McDonough, Michelle K. Smith, Nnadozie Okoroafor, Hannah Jordt, and Mary Pat Wenderoth. 2014. “Active Learning Increases Student Performance in Science, Engineering, and Mathematics.” Proceedings of the National Academy of Sciences 111 (23): 8410–8415. https://doi.org/10.1073/pnas.1319030111.

Online-only journal article

In-text citation:

Online learning can match or exceed traditional classroom outcomes when designed intentionally (Means et al. 2021).

Reference list entry:

Means, Barbara, Marianne Bakia, Robert Murphy, and Karla Jones. 2021. “Learning Online: What Research Tells Us about Whether, When, and How.” Journal of Online Learning Research 7 (1): 1–20. https://www.learntechlib.org/p/216456/.

Government or institutional report

Here’s a real-world style example using a US government source.

In-text citation:

According to recent data, teen e-cigarette use has shifted toward flavored products (Food and Drug Administration 2023, 5).

Reference list entry:

Food and Drug Administration. 2023. Youth Tobacco Use: E-Cigarette Trends and Patterns. Silver Spring, MD: U.S. Department of Health and Human Services. https://www.fda.gov/tobacco-products.

Reports like this are common in health, policy, and education papers, so it’s helpful to keep this example of a format in your notes.

Websites and online sources: examples include organizational authors and missing dates

Web sources can be messy, so this is where students usually want the best examples of Chicago style author-date system they can copy and adapt.

Organization as author (health example)

In-text citation:

Regular physical activity can significantly reduce the risk of chronic disease (Mayo Clinic 2024).

Reference list entry:

Mayo Clinic. 2024. “Exercise: 7 Benefits of Regular Physical Activity.” Last modified January 10, 2024. https://www.mayoclinic.org/healthy-lifestyle/fitness.

Webpage with individual author

In-text citation:

Time-blocking can help students manage large research projects more effectively (Harper 2023).

Reference list entry:

Harper, Melissa. 2023. “How to Break Down a Research Paper into Manageable Tasks.” Harvard College Writing Center. October 5, 2023. https://writingcenter.fas.harvard.edu.

No date available

If there’s no publication date, Chicago author-date uses n.d. (no date).

In-text citation: (National Institutes of Health n.d.)

Reference list entry:

National Institutes of Health. n.d. “Understanding Clinical Trials.” Accessed April 2, 2025. https://www.nih.gov/health-information/nih-clinical-research-trials-you.

This is one of those quiet but important examples of Chicago style author-date system examples to remember: n.d. in place of the year, and an “Accessed” date for undated web content.

Multiple authors, same year, and repeated citations: tricky but simple with good examples

Now let’s tackle some situations that cause confusion, using real examples to show how Chicago author-date handles them.

Same author, same year

If you cite more than one work by the same author from the same year, you add letters (a, b, c) after the year.

In-text citations:

(Lopez 2022a, 15)
(Lopez 2022b, 203)

Reference list entries:

Lopez, Maria. 2022a. Digital Literacy in Urban High Schools. New York: Routledge.

Lopez, Maria. 2022b. Teachers and Technology: Case Studies in Classroom Innovation. Boston: Pearson.

Different authors with the same last name

Include initials in the reference list and use first names in the text if needed for clarity.

In-text citations:

(J. Kim 2021, 44)
(S. Kim 2021, 88)

Reference list entries:

Kim, Jason. 2021. Student Motivation in Hybrid Classrooms. Chicago: University of Chicago Press.

Kim, Sophia. 2021. Assessment and Feedback in Online Learning. New York: Springer.

Repeated citations in the same paragraph

Chicago author-date does not use “ibid.” — you just repeat the in-text citation as needed. If you cite the same source multiple times in a row, you can leave out the year in some disciplines, but many instructors prefer you keep the full (Author Year, page) format each time for clarity.

For example:

Active learning improves exam performance for most students (Freeman et al. 2014, 841). These gains are especially strong in large lecture courses (Freeman et al. 2014, 842).

This is one of the simplest but best examples to remember: no “ibid.” in the author-date system.

Citing AI tools and datasets: 2024–2025 style examples

Because you’re working in 2024–2025, you’ll likely be asked to cite AI tools or datasets. Chicago’s author-date system is still evolving here, but you can follow guidance from major universities and adapt.

Example of citing an AI tool (like a chatbot)

Many institutions recommend treating AI tools like software or apps. Always follow your instructor’s policy, but here’s a sample format.

In-text citation:

(OpenAI 2025)

Reference list entry (sample):

OpenAI. 2025. ChatGPT (March 2 version). Accessed March 5, 2025. https://chat.openai.com/.

If you’re quoting or paraphrasing specific AI output, some schools ask you to describe it in the text as well, for example: “According to a response generated by ChatGPT (OpenAI 2025)…”. Check your institution’s guidelines; many writing centers now have updated pages on citing AI.

Example of citing a dataset

In-text citation:

(World Bank 2024)

Reference list entry:

World Bank. 2024. World Development Indicators 2024. Data set. Washington, DC: World Bank. https://datacatalog.worldbank.org.

These newer examples of Chicago style author-date system examples show how flexible the system is, even with modern sources.

Building a reference list: putting all the examples together

To see how everything fits, imagine the end of a student paper that uses several of the sources above. A short reference list using the Chicago author-date system might look like this:

Booth, Wayne C. 2016. The Craft of Research. 4th ed. Chicago: University of Chicago Press.

Centers for Disease Control and Prevention. 2024. “COVID-19 Vaccination: Trends and Coverage.” Last modified March 15, 2024. https://www.cdc.gov/coronavirus/2019-ncov/vaccines.

Freeman, Scott, Sarah L. Eddy, Miles McDonough, Michelle K. Smith, Nnadozie Okoroafor, Hannah Jordt, and Mary Pat Wenderoth. 2014. “Active Learning Increases Student Performance in Science, Engineering, and Mathematics.” Proceedings of the National Academy of Sciences 111 (23): 8410–8415. https://doi.org/10.1073/pnas.1319030111.

Garcia, Ofelia. 2020. “Assessing Multilingual Learners in the 21st Century Classroom.” In Rethinking Assessment in Education, edited by Linda Darling-Hammond and Pedro Noguera, 80–102. New York: Teachers College Press.

Mayo Clinic. 2024. “Exercise: 7 Benefits of Regular Physical Activity.” Last modified January 10, 2024. https://www.mayoclinic.org/healthy-lifestyle/fitness.

Nguyen, Linh, and Priya Patel. 2023. “Social Media and Vaccine Hesitancy among Young Adults.” Journal of Public Health Research 15 (2): 110–130. https://doi.org/10.1234/jphr.2023.5678.

OpenAI. 2025. ChatGPT (March 2 version). Accessed March 5, 2025. https://chat.openai.com/.

Rosenberg, Daniel. 2020. Health Communication in the Digital Age. New York: Oxford University Press.

If you compare this to all the earlier examples of Chicago style author-date system examples, you’ll see the same pattern repeated: author, year, title, and then whatever publication details make sense for that type of source.

Quick FAQ: common questions about Chicago author-date examples

What are some common examples of Chicago style author-date in-text citations?

Common examples of in-text citations in Chicago author-date look like:

• Paraphrase from a book: (Booth 2016, 72)
• Quote from a journal article: (Freeman et al. 2014, 841)
• Webpage with organization as author: (Mayo Clinic 2024)

The key is always author + year, with page numbers when you’re pointing to a specific part.

Can you give an example of a Chicago author-date citation for a website with no author?

Yes. Use the organization as the author if possible. For example:

• In-text: (National Institutes of Health n.d.)
• Reference list: National Institutes of Health. n.d. “Understanding Clinical Trials.” Accessed April 2, 2025. URL.

If there truly is no author or organization, Chicago allows you to start with the title, but most academic websites have at least an institutional author.

Do I need page numbers in every Chicago author-date citation?

No. Page numbers are used when you quote or refer to a specific part of a source, especially for books and articles. For general references to an entire work, (Author Year) is enough. For example, (Rosenberg 2020) is fine if you’re talking about the book as a whole.

Where can I check more official examples of Chicago style author-date system examples?

For more detailed guidance and additional examples of Chicago style author-date system examples, you can check:

• The Chicago Manual of Style Online (via many university libraries)
• Your university’s writing center pages, such as those at Harvard or Purdue
• Government and health sites that model good citation of research, like CDC or NIH

Using these along with the real examples in this guide will keep your citations consistent and professional.