Q. A few years ago, Vox published an article making a distinction between titles, subtitles, and “reading lines” for books (“ ‘A Novel’: An Article,” by Eliza Brooke, February 14, 2019). The article claimed that when a work has the form of Title of Book: A Novel, “A Novel” is not a true subtitle but instead “explains its contents to a potential reader and serves as a useful signpost when you’re rooting through an unsorted stack of books.” How should these “reading lines” be treated in citations? If they appear not solely on the book cover but also on the title page, it would seem to me that they should be treated as a subtitle. Is that right? Or should these reading lines be omitted since they are not real subtitles as argued in the Vox article, and if so, what is a good guideline for distinguishing them from subtitles?
A. Assuming authorship and other relevant details have been supplied, most books can be identified from a main title alone. Subtitles are often informative, though, so we would advise including them in the titles of books that have them at least once, as on first mention or in a full note or bibliography entry.
But we agree with the Vox article that a subtitle that merely identifies a book’s genre isn’t a proper subtitle. The phrase “A Novel” does that, so you can leave it out, even if it appears on the title page (see also CMOS 13.91). By contrast, you’d want to include a subtitle like the one for the book All the Ways We Said Goodbye: A Novel of the Ritz Paris, by Beatriz Williams, Lauren Willig, and Karen White (William Morrow, 2020).
Not that there’s anything wrong with including a generic subtitle in a source citation, especially if it appears on the title page. But when that subtitle is shared with countless other books and doesn’t say anything special, it’s usually safe to omit it.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Here’s a funny question. How do you treat a source where the author name or pseudonym is the same as the name of the website or blog? Is there a way to eliminate repetition from the entries below?
Mercer, Ilana. 2017. “Article Title.” IlanaMercer.com. August 1.
Bionic Mosquito. 2015a. “Blog Post Title.” Bionic Mosquito, August 5.
Thank you!
A. Your first author-date reference list entry, for the Mercer article, is fine as is. It’s clear that a URL featuring the author’s name must be the author’s website. It also happens to reflect the website’s copyright line: “© 2008-2025 ILANAMERCER.com”; applying caps to only the I and M (domain names aren’t case sensitive) increases legibility.
Your second entry is also fine as is. Most readers would figure out that the italics for the second instance of Bionic Mosquito mean that it’s a title rather than an author or publisher. But you can help readers out a little with one or two clarifications:
Bionic Mosquito [pseud.]. 2015a. “Blog Post Title.” Bionic Mosquito (blog), August 5.
We’d recommend adding that first one—which clarifies that “Bionic Mosquito” is a pseudonym (the square brackets show that it’s an editor’s interpolation). The parenthetical description “(blog)” is less important to include but could be helpful for an audience that may not know the source material. In both cases, include a full URL at the end of the citation—or, in published form, provide a link from the title or elsewhere. See also CMOS 13.6, 13.82, and 14.105.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. When a printed work misspells an author’s name, how should that name be represented in notes and bibliography entries for that work? Should the misspelled name be used, silently corrected, or somehow pointed out? If the author on the title page is “Ezra Fisk” but the correct spelling is “Ezra Fiske,” might we use “Fisk[e], Ezra” as the bibliography entry? I suppose that similar questions could also be asked of typos in other bibliographic information.
A. Your solution is a good one. But not all readers can be expected to understand the nuances of bracketed insertions, so you could instead do something more explicit than a bracketed e:
Fiske, Ezra [spelled “Ezra Fisk” on the title page]. Title of Work. Publisher, date.
Readers will then be more likely to know what to expect when tracking down the cited source. (If the variant spelling occurs on more than the title page, adjust the bracketed comment accordingly.) For additional considerations, start with CMOS 13.82; see also 12.70.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. For author-date parenthetical text references, CMOS 13.123 says to list “as many [authors] as needed to distinguish the references.” My reference list includes two articles where the first seven authors are the same. In that case, can I use the letters instead of listing more authors? The articles are both from 2006 in the journal Latin American Antiquity: “Smokescreens in the Provenance Investigation of Early Formative Mesoamerican Ceramics” and “Methodological Issues in the Provenance Investigation of Early Formative Mesoamerican Ceramics.”
A. Yes, you can use letters to differentiate the two articles in your text. Per CMOS 13.107, a source by more than six authors would be listed in your references by the first three, followed by et al. Because the first three authors are identical for those two articles (each of which lists thirteen authors), adding a and b after the year of publication would distinguish them in the text. Here are the reference list entries (in alphabetical order by title; see 13.114) and text citations:
Neff, Hector, Jeffrey Blomster, Michael D. Glascock, et al. 2006a. “Methodological Issues in the Provenance Investigation of Early Formative Mesoamerican Ceramics.” Latin American Antiquity 17 (1): 54–76. https://doi.org/10.2307/25063036.
Neff, Hector, Jeffrey Blomster, Michael D. Glascock, et al. 2006b. “Smokescreens in the Provenance Investigation of Early Formative Mesoamerican Ceramics.” Latin American Antiquity 17 (1): 104–18. https://doi.org/10.2307/25063039.
(Neff et al. 2006a)
(Neff et al. 2006b)
Alternatively, you could cite by title in the text (and omit the letters in the reference list entries and text citations):
(Neff et al., “Methodological Issues,” 2006)
(Neff et al., “Smokescreens,” 2006)
But the letters are more concise.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Hello! I am providing guidance to art history students on creating bibliography and note entries and have a few questions that I’m not sure of the answer to: (1) How would one style the name Hans Holbein the Younger in a bibliography entry? (2) When a work of art doesn’t have a title and is simply a description, I assume it would be in sentence case and not italicized, but is this correct? For instance, this glass ribbed bowl at the Met. (3) I assume for guesstimate dates “ca.” would be preferred, but would “18th century” or “Edo period” be acceptable?
A. (1) For an item in a bibliography attributed to Hans Holbein the Younger, invert the name as “Holbein, Hans, the Younger.” (2) Yes, sentence case would be appropriate for a description in lieu of a title:
Glass ribbed bowl. 1st century BCE. Cast, tooled, and cut. Height 2 9⁄16 in. (6.5 cm), diameter 5 7⁄16 in. (13.8 cm). Metropolitan Museum of Art, New York. Object no. 17.194.197.
(3) Yes, a specific century or named era, if known, can be used instead of “ca.” (about), which usually applies to a more specific date such as a year. In some cases, it will be appropriate to combine a named period with an estimated date (e.g., Edo period, ca. 1800).
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. I’m wondering how you would treat an online report from an NGO or watchdog organization? What type of source is it parallel to? I’m asking to instruct my students for the author-date format. There is no specific author, just the organization. There is a specific date of publication, not just a year. This is the specific source, but there are others that are similar: https://humena.org/political-satire-in-egypt-a-peaceful-protest-against-repression/. Thank you.
A. Reports are covered briefly under CMOS 14.117, but you’ll also want to refer to 13.86 and 13.127, which show how to handle organizations as authors, including the use of abbreviations in author-date format.
Most freestanding reports can be cited similarly to books. The report at the URL you point to could be cited in a reference list as follows:
HuMENA and RedWord. 2024. Political Satire in Egypt: A Peaceful Protest Against Repression. HuMENA for Human Rights and Civic Engagement in collaboration with RedWord for Human Rights and Freedom of Expression, November 22. https://humena.org/political-satire-in-egypt-a-peaceful-protest-against-repression/.
As with many such documents, the author and publisher are the same. By abbreviating the author, you allow for concise citations in the text. The example above would be cited as “(HuMENA and RedWord 2024).”
Note that the report itself (published as a PDF file) doesn’t seem to list a date of publication, but the page that offers the PDF and announces its publication does have a date, which you can cite as shown above.
For working papers and the like, see CMOS 14.116.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Why do you use a colon to separate page numbers in a journal article citation but a comma to separate page numbers in most everything else? It seems completely nonsensical.
A. You’re right, a comma might make more sense. Somewhere along the line, however, the idea that a colon should come between a volume and page number morphed into Chicago’s current journal citation style. The following example, from the Botanical Gazette, appeared in the first ten editions of the Manual (the 1 in parentheses was used to mark the first of two examples by the same author):
LIVINGSTON, B. E., (1) On the nature of the stimulus which causes the change in form of polymorphic green algae. BOT. GAZ. 30:289–317. 1900.
That was offered not as an example of Chicago style but of Gazette style. Today, that same article can be found on the website of the International Journal of Plant Sciences (which continues the Gazette, a journal that got its start in 1876) and would be cited in modern Chicago style as follows:
Livingston, Burton Edward. “On the Nature of the Stimulus Which Causes the Change of Form in Polymorphic Green Algæ.” Botanical Gazette 30, no. 5 (1900): 289–317. https://doi.org/10.1086/328048.
An issue number and date now intervene between volume number and page range, but that colon nonetheless became Chicago style for citing journal articles, starting with the 12th edition (published in 1969). That was also the first edition to prefer Arabic rather than Roman numerals for volume numbers (the Gazette example was an exception to this rule in earlier editions), which may have factored into the decision. A colon remains Chicago style for referring to a volume and page number alone, as in “2:37” (for vol. 2, p. 37); see CMOS 14.74. Older Chicago style would have called for “II, 37” (with a Roman numeral and a comma, as in the 10th ed., ¶ 253).
The editors of the 12th edition could have specified a comma whenever a year or other number intervenes between volume and page numbers (as is the case for most journal article citations), but they didn’t. More than fifty years later, our editors have come to think of that colon as a helpful little sign that says journal article.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. A paper includes the following references:
Tawiah, Vincent, Ernest Gyapong, and Muhammad Usman. 2024. “Returnee Directors and Green Innovation.” Journal of Business Research 174 (March): 114369.
Tawiah, Vincent, Ernest Gyapong, and Yan Wang. 2024. “Does Board Ethnic Diversity Affect IFRS Disclosures?” Journal of Accounting Literature, ahead of print, September 24.
Tawiah, Vincent, Reon Matemane, Babajide Oyewo, and Tesfaye T. Lemma. 2024. “Saving the Environment with Indigenous Directors: Evidence from Africa.” Business Strategy and the Environment 33 (3): 2445–61.
Tawiah, Vincent, Abdulrasheed Zakari, and Rafael Alvarado. 2024. “Effect of Corruption on Green Growth.” Environment, Development and Sustainability 26 (4): 10429–59.
Should I still cite the first two references in the text as first author, second author, et al. YEAR (e.g., Tawiah, Gyapong, et al. 2024), even though only one author is not mentioned and so “et al.” doesn’t seem appropriate?
A. It would be nice if et al. (a Latin abbreviation meaning “and others”) could be used to refer to just one person, but it’s plural, and there’s no suitable alternative abbreviation for the singular.
In your situation—where you are obligated to include more than one name in your parenthetical author-date text references to distinguish between different works published in the same year by the same first-listed author but with different coauthors (otherwise, “Tawiah et al.” would suffice)—you have no choice but to include all three authors when citing any of the three sources by exactly three authors.
But you can still use et al. for the source by four authors (the article in Business Strategy and the Environment), where it would stand in for the names of the third and fourth authors (Oyewo and Lemma):
(Tawiah, Gyapong, and Usman 2024)
(Tawiah, Gyapong, and Wang 2024)
(Tawiah, Zakari, and Alvarado 2024)
but
(Tawiah, Matemane, et al. 2024)
Note that you’d need to list all three authors for the first two examples no matter what—because the first two authors are the same for both. It’s the third example (with coauthors Zakari and Alvarado) that requires all three names simply because et al. must refer to more than one person.
For some additional considerations (including the option to use a short title to differentiate such sources in text references, which would allow you to cite “Tawiah et al.” for all four of your sources), see CMOS 13.123. For the article ID in place of page numbers in the “Returnee Directors” citation, see CMOS 14.71. For the meaning of “ahead of print” in the Accounting Literature example, see CMOS 14.75.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. When citing an endnote, should the page number be the page the note callout appears on or the page where the endnote is at the end of the book (24n5 vs. 385n5)?
A. Footnote or endnote, you’re citing the note itself, not its reference number in the text. For an endnote, the page number to cite is the one at the end of the book where the note can be found (or 385n5 in your example).
This does mean that readers who follow the citation to its source will need to track down the note reference in the text if they want to see the context for that note, but endnotes are almost always less user-friendly than footnotes (unless the notes are linked, as in an ebook).
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. I’m in the middle of working with a client on a white paper that has citations to articles found on government agency websites (e.g., Centers for Disease Control and Prevention, National Institutes of Health, Office of Disease Prevention). The writing is completed, we’re in the layout/production stage, and while checking links and confirming URLs in the endnotes, we’re finding that articles and pages that had been referenced in our endnotes have now been removed from the government websites in accordance with the administration’s recent orders. How do we reference reports and articles that are significant but have been removed?
A. Whenever you find a dead link (or a link that works but points to a different version of the cited content), you have a few options, which are the same regardless of why the link no longer works as intended:
- If the cited page can’t be found anywhere, and the author didn’t save a copy, then you can either (a) add “(page no longer available)” or similar wording after the URL (as shown at CMOS 14.104), or (b) ask the author to revise the text and citation to fix the problem (perhaps by referring to and citing a different document). Option a should be used only as a last resort.
- If the author did save a copy, you can add that fact to the notice suggested for option a above: “(page no longer available; copy of original in author’s possession).” Option 1b may still be preferable unless the cited document is crucial to the author’s paper.
- If you can track down an archived version of the page—for example, at the Internet Archive’s Wayback Machine—you can cite that (after making sure that any text that relies on that page, including any direct quotations, remains accurate).
Option 3 is usually best, assuming the content has been archived in a way that allows others to consult it. For example, consider the following URL, which as of March 4, 2025, results in a “Page Not Found” notice:
https://www.cdc.gov/healthcommunication/Health_Equity.html
If you paste that URL into the Wayback Machine, you’ll find dozens of archived versions (or snapshots) dating back to August 25, 2021. Here’s how we’d cite one of those versions, following the recommendations at CMOS 14.104 (and using the “last reviewed” date reported at the bottom of that page in lieu of a publication date; see CMOS 13.16):
1. “Health Equity Guiding Principles for Inclusive Communication,” Gateway to Health Communication, CDC, last reviewed August 11, 2023, archived July 24, 2024, at https://web.archive.org/web/20240724170713/https://www.cdc.gov/healthcommunication/Health_Equity.html.
If you can’t find the page at the Wayback Machine or anywhere else, you’re back to options 1 and 2 at the beginning of this answer.
Links break for many reasons, but there are some basic precautions that authors can take to prevent the scenario described in the question above from happening in the first place:
- First, always save a copy of any web page (including any PDFs) that you consult as you do your research (e.g., as a screenshot or as an HTML or PDF file). Zotero and other citation managers can help with this task. See also CMOS 13.13 and 13.17.
- Second, don’t assume that a page will have been archived by someone else (as was the case for the CDC.gov URL in the example above). Instead, create your own archived version if you can—for example, by pasting the URL into the Save Page Now feature at the Wayback Machine. This won’t always be an option (some content will be blocked from being archived), but at least you’ll have your own personal copy to point to (see previous bullet) if anyone challenges your research.
Copyeditors can help by alerting authors to any page that may need to be archived or saved in one of the ways described above—and by editing citations accordingly. That should keep everyone, including readers, on the same page.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]