Introduction to the Chicago Manual of Style

The biggest challenge for first-time authors is citing sources. Sometimes, it seems as though compiling sources and citing them took longer than the writing. The main source of style guidance when citing sources is the Chicago Manual of Style (CMOS), APA (The American Psychiatric Association) and MLA (The Modern Language Association) styles. Compared to APA and MLA, the CMOS is the most common style of citing sources in books.

To try to make the task less laborious for you when learning about the Chicago Manual of Style, I’m going to give you a brief introduction to some of its main citation guidelines and how to apply them correctly to your own writing.

The CMOS began life in 1891 when the University of Chicago Press was first established. Even at that time, typesetters regularly had to work with all kinds of different fonts. The texts were deciphered by the compositors, who then passed them on to the proofreaders to rework any inconsistencies and typographical errors before the final printing.

To keep a standard system for reviewing all these texts, the staff drew up a standard set of rules which they passed on to the rest of the university. Over time, what had started as a simple sheet of rules evolved into a pamphlet, and kept on growing and developing organically over the years until today, when the CMOS is in its 17th edition. To know about the fascinating history and origins of the Chicago Manual of Style, click here.

There are two variations for citing sources when using the Chicago Manual of Style, which I’m going to explain in this article:

  1. Notes & Bibliography

This system is primarily used when writing on historical topics. In this variation, the source that is quoted in the main text—which can either be paraphrased into one’s own words or quoted directly—will be denoted as a quotation by having a superscripted number, starting from 1 upwards, placed after it within the text. With footnotes, this superscripted number corresponds to a relevant footnote found at the bottom of the same page. Endnotes are similarly superscripted but are located at the end of the work. Despite this difference, both are cited in precisely the same manner.

I.A Placement

As previously mentioned, footnotes are used when somebody else’s words are either paraphrased or directly quoted within your own writing to demonstrate a point. The superscripted source number appears at the end of a sourced sentence after any punctuation marks, except for a dash. An example will explain this:

Example 1: Superscript Placement

The sentence includes an idea from someone else’s book, paraphrased in my own words.1 This is a “quote from another book”2—but most scholars disagree with the argument it proposes.

All footnotes are numbered consecutively throughout the entirety of a book and never restart at 1 for any reason.

I.B Short Notes and Full Notes

In the CMOS, there are two kinds of footnotes: Short Notes and Full Notes.

Full notes are always used in works that don’t have a bibliography so that all relevant information relating to the source is maintained. This is because a full note is always used for the first footnote of every new source, regardless of whether the work includes a bibliography or not.

However, it’s important to note that full notes are written differently according to their source. This is shown below in the following examples. Note the exacting use of capitalized author/editor names and titles of works, the italicized book/journal/website names, as well as the use of commas, colons, periods, and brackets to separate the different elements of the citation, which are all required when using the CMOS:

  1. Books

Author’s first name and last name, “Chapter Title,” in Book Title, ed. editor(s) name (Press name: full press name), Page number(s) (separated by a hyphen if more than one, e.g., 12 – 17. and followed by a period), URL [if online].

  1. Journal Articles

Author’s first name and last name (no comma to separate), “Article Title,” Journal Name Volume, Issue number (Year): page number(s), DOI or URL.

  1. Websites

Author’s first name and last name, “Page title,” website title, publication date, URL.

Short notes are used for works that include a bibliography. However, a full note must be used for the first citation of every source, whereas a short note is used for all consecutive citations of the same source.

The correct use of short notes according to the CMOS is demonstrated below for the following sources:

  1. Books

Author’s last name, “Chapter Title,” Page number(s).

  1. Journal Article

Author’s last name, “Shortened Article Title,” Page number(s).

  1. Website

Author’s last name, “Shortened Page Title.”

In examples 2 and 3 that follow, the correct usage of full notes and short notes is explained in different contexts when the source is a book:

Example 2: Full Notes & Short Notes

This example demonstrates the use of footnotes when the source is a book.3 This is the other sentence from the same source.4 This, however, is from an entirely new source.5 But now I’m going to refer to a previously used source for another idea.6  This is how the two different types of notes should look when correctly laid out according to the CMOS:


  1. Merwyn D’Silva, “On Full Notes,” in D’Silva’s Book, ed. Michael Jackson (Random: Random University Press), 20.
  2. D’Silva, “On Full Notes,” 20.
  3. Rahul Sharma, Sharma’s Book on Dictations and Citations, ed. Johann Fletcher (Another: Another University Press), 47.
  4. D’Silva, “On Short Notes,” 30.

However, if there is more than one source per sentence, then these are written under one footnote with each citation separated by a semicolon.

Additionally, if a book title contains more than four words, then its title is shortened in the short note.

So, remember, if you’re repeating the mention of a specific source, you must use the short notes format.

Example 3: Multiple Sources in One Sentence and Shortened Book Titles

Here’s a sample sentence that demonstrates the correct format for full and short notes when citing multiple sources:

One author claims that this idea is incorrect, even though his professor writes otherwise.7


  1. Sharma, Citations and Dictations, 19; Edward Banks, “Same Day, Different Idea,” in Edward’s Book ed. Yeng Xiao (Dartwood: Dartwood University Press), 89.

I.C Journal Articles and Websites

Examples 4 and 5 explain about citing journal articles and websites using both full notes and short notes:

Example 4: Journal Article

In a journal article, this is the correct format for full and short footnotes. Note the shortened title in the short note:

This example will demonstrate the use of footnotes when the source is a Journal Article.8 This is a filler sentence before the next sentence. This idea comes from the same source as the first sentence.9



  1. Merwyn D’Silva, “The Chicago Manual of Style: History & Origins,” Journal of Citations52, no. 2 (2020): 222,
  2. D’Silva, “Chicago Manual History,” 222.

Example 5: Websites

This shows the correct use of full and short footnotes for citing a website. Note the shortened title in the short note:

This example demonstrates the use of footnotes when the source is a website.10 This is a filler sentence before the next sentence. This idea comes from the same source as the first sentence.11


  1. Jack D’Silva, “How to Cite Chicago Manual Style,” SomeWebsite, April 18, 2018, citing-sources/ how-to-cite-Chicago-manual-style/.
  2. D’Silva, “Citing Chicago Manual Style.”

I.D. Multiple Authors

If, as is often the case, a footnote has two or three authors, then all the names should be included. If there are four or more authors, you can use “et al.” after the first author’s name, which means ‘and so on’ and saves, including all the names. Here are a few examples:

Two Authors

Full Note: Renelle D’Silva and Cheng Yang …

Short Note: D’Silva and Cheng …

Three Authors

Full Note: Renelle D’Silva, Cheng Yang, and Martin Vasquez…

Short Note: D’Silva, Yang, and Vasquez…

Four or more authors:

Full Note: Robert D’Silva et al. …

Short Note: D’Silva et al. …

I.e., Dealing with Missing Information

There will be situations when your sources may not have all the information specified by the CMOS as necessary to correctly fill out the citation. When that happens, just try to fill in as much information as is available.

If a source doesn’t have page numbers but you still want to cite it, it’s perfectly acceptable to cite the chapter or paragraph number, shortening them to “chap.” or “para.”, respectively. Note that neither are capitalized.

For example:

  1. D’Silva, “Some Journal Article,” chap. 3
  2. D’Silva, “Some other Journal Article,” under “How to Cite.”

Similary, if the source lacks a publication date, the CMOS allows you to replace the date with “n.d.”, an abbreviation for ‘no date.’

In the unlikely event that the name of your source is unknown and you cannot cite it, then it’s fine to simply begin the citation with the organization’s name instead. For example:

  1. SomeRandomWebsite, “Chicago Citations.”

I.F Bibliography

A bibliography is only really necessary when a work lacks detailed footnotes or endnotes. However, the CMOS still recommends showcasing one at the end of your work, as it gives readers a handy reference point for further reading.

I’ve set out below the correct CMOS method for formatting a bibliography for different types of sources. As you can see, it’s important to fill in as much information as possible, so that the source is easily found by readers. Also, keep in mind that all lines of a source in the bibliography, except for the first line, are indented.


Author last name, first name. “Chapter Title.” In Book Title, edited by editor first name and last name, page range. Place of Publication: Publisher, Year.

D’Silva, Steve. “On Bibliography.” In How to Use the Chicago Manual of Style, edited by Yeng Su, 221-90. Bangalore: Random Press, 2020.

Journal Article:

Author last name, first name. “Article Title.” Journal Name Volume, Issue number (Publication date): Page range. DOI or URL.

Andreff, W., and P. D. Staudohar. “The Evolving European Model of Professional Sports Finance.” Journal of Sports Economics 1, no. 3 (August 2000): 257–276.


Author last name, first name. “Page Title.” Website name. Publication date. URL.

In the case of websites, the format differs slightly, as, unlike books, they are frequently updated, so the following format is used:

Website name. “Title.” Accessed on Month, Date, Year. Link Wikipedia. “Data analysis.” Accessed on August 15, 2019.

I.G. Footnotes vs. Endnotes

As I pointed out earlier, the only major difference between footnotes and endnotes is that footnotes always appear at the foot of the same page where the source is quoted or paraphrased. Endnotes, as the name suggests, are always placed at the end of a work.

You’ll note that while footnotes make the sources more accessible, they can also make the page appear rather cluttered. Endnotes are not so easily accessible as footnotes, but they don’t make the page seem cluttered within the main text.


This variation is mostly used in academic writing in the fields of science and the social sciences. It consists of two parts: First, an in-text citation consisting of the author’s last name, year of publication, and a page number (if necessary). The second part consists of a reference list comprised of entries corresponding to sources used in a scientific paper.

II.A In-Text Citations

It includes the author’s last name followed by the year of publication without a comma separating them. If necessary, especially when quoting or referring to a specific part of a source, the page number or page-range is added after a comma. Here are some examples showing the correct formats:

Example 1: In-Text Citation

In-text Citation Format: (Author last name Year of publication, Page number)

Example: (D’Silva 2020) or (D’Silva 2020, 11-13)

II.A.1 Placement of In-Text Citations

An in-text citation usually appears at the end of a related clause, quote, or sentence. If multiple sources are used within a sentence, then they are always separated by a semicolon.

Example 2: Placement of In-Text Citation

This is an idea taken from two sources, both of which talk about chickens and geese (D’Silva 2019; Chang 2019), but new research about falcons disproves this idea (Cortez 2020).

HOWEVER, if a researcher’s name appears within the sentence itself, then you need only cite the year and page number (if relevant) inside the parenthesis.

Example 3: Placement of In-Text Citation with Author’s Name in Sentence

D’Silva (2019, 19) has suggested in his research that chickens can run for 100 meters without taking a break. However, Cortez’s (2020) experiment on falcons chasing chickens has disproved this.

II.B Bibliography / Reference List

In the in-text variation, a Reference List is the equivalent of the bibliography. Examples for formatting correctly for various sources are shown below:


Author’s last name, first name. Year. Book Title. Edition. Place of publication: Publisher. URL.

García Márquez, Gabriel. 1988. Love in the Time of Cholera. Translated by Edith Grossman.                               London: Cape.

Author’s last name, first name. Year. “Chapter Title.” In Book Title, edited by editor(s) first name and last name (note no comma used to separate first and last names), Page range. Place of publication: Publisher.

Stewart, Bob. 2007. “Wag of the Tail: Reflecting on Pet Ownership.” In Enriching Our Lives with                        Animals, edited by John Jaimeson, 220–90. Toronto: Petlove Press.

Journal Article:

Author’s last name, first name. Year. “Article Title.” Journal Name Volume, Issue number (Publication date): Page range. DOI or URL.

Andreff, W., and P. D. Staudohar. 2000. “The Evolving European Model of Professional Sports Finance.” Journal of Sports Economics 1, no. 3 (August): 257–276.


Author last name, first name. Year. “Page Title.” Website name. Access/revision date. URL.

Smith, John. 2019. “Creating a Chicago Heading.” Publishedge. Updated September 12, 2019.

II.C Multiple Authors

Below I’ve set out some examples of how to correctly cite multiple authors:

II.C.1 In-Text Citation

2 authors: (Grazer and Fishman 2015)

3 authors: (Berkman, Bauer, and Nold 2011)

4+ authors: (Johnson et al. 2016)

II.C.2 Reference List

A source in the reference list can have up to ten authors’ names included, which are always alphabetized. In this format, note that all names, excluding the first, are not inverted. If there are eleven or more authors, then you can apply the same rule of using “et al.” after the first seven names.

Gmuca, Natalia V., Linnea E. Pearson, Jennifer M. Burns, and Heather E. M. Liwanag. 2015. “The Fat and the Furriest: Morphological Changes in Harp Seal Fur with Ontogeny.” Physiological and Biochemical Zoology 88, no. 2 (March/April):158–66.

When multiple sources of the same author from the same year are cited, the addition of a lower-case letter from ‘a’ through ‘z’ is used as an identifier to distinguish each in the reference list:


D’Silva, Robert. 2020a. …

D’Silva Robert. 2020b. …

For the in-text citation, the format is (Last name Year a), (Last name, Year b), etc.

II.D Missing Information

As mentioned earlier, there will be cases when you don’t have all the information to cite according to the usual format. If, for example, a source doesn’t include a date, it’s fine to replace the date with “n.d.” (no date) for both the in-text citation and the reference list, as in the following examples.


(D’Silva n.d.)

D’Silva, Renelle. n.d. Example Book. New York: Norton.

If a source doesn’t include the author’s name, you can use the name of the organization instead, as shown below:


(University of Glasgow 2019)

University of Glasgow. 2019. “Colombian River Guardians Rally Support in Scotland.” October 14, 2019.

However, if a source is explicitly stated as anonymous, then simply use the word “Anonymous” in place of the author’s name in the in-text citation and reference list.

There are many variations in formatting sources correctly when there’s a lack of the usual information, and each case has to be treated differently. However, you will find detailed directions on citing these sources in the proper way by accessing the CMOS website. However, I hope that, for most of your citations, this brief guide will provide you with the fundamentals on how to cite sources correctly according to CMOS style in your non-fiction writing.

“Always cite your sources!” Don’t risk getting into trouble with plagiarism—it’s not worth the trouble!

Image credit: Staff of the University of Chicago Press / Public domain

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