Please note that although these resources reflect the most recent updates in the The Chicago Manual of Style (17th edition) concerning documentation practices, you can review a full list of updates concerning usage, technology, professional practice, etc. at The Chicago Manual of Style Online.
The Chicago Manual of Style (CMOS) covers a variety of topics from manuscript preparation and publication to grammar, usage, and documentation, and as such, it has been lovingly dubbed the “editor's bible.”
The material on this page focuses primarily on one of the two CMOS documentation styles: the Notes-Bibliography System (NB), which is used by those working in literature, history, and the arts. The other documentation style, the Author-Date System, is nearly identical in content but slightly different in form and is preferred by those working in the social sciences.
Though the two systems both convey all of the important information about each source, they differ not only in terms of the way they direct readers to these sources, but also in terms of their formatting (e.g., the position of dates in citation entries). For examples of how these citation styles work in research papers, consult our sample papers:
Author-Date Sample Paper
NB Sample Paper
In addition to consulting The Chicago Manual of Style (17th edition) for more information, students may also find it useful to consult Kate L. Turabian's Manual for Writers of Research Papers, Theses, and Dissertations (8th edition). This manual, which presents what is commonly known as the "Turabian" citation style, follows the two CMOS patterns of documentation but offers slight modifications suited to student texts.
The Chicago Notes and Bibliography (NB) system is often used in the humanities to provide writers with a system for referencing their sources through the use of footnotes, endnotes, and through the use of a bibliography. This offers writers a flexible option for citation and provides an outlet for commenting on those sources, if needed. Proper use of the Notes and Bibliography system builds a writer’s credibility by demonstrating their accountability to source material. In addition, it can protect writers from accusations of plagiarism, which is the intentional or accidental uncredited use of source material created by others.
In the Notes and Bibliography system, you should include a note (endnote or footnote) each time you use a source, whether through a direct quote, paraphrase, or summary. Footnotes are added at the end of the page on which the source is referenced, while endnotes are compiled at the end of each chapter or at the end of the entire document.
In either case, a superscript number corresponding to a note, along with the bibliographic information for that source, should be placed in the text following the end of the sentence or clause in which the source is referenced.
If a work includes a bibliography, which is typically preferred, then it is not necessary to provide full publication details in notes. However, if a bibliography is not included with a work, the first note for each source should include all relevant information about the source: author’s full name, source title, and facts of publication. If you cite the same source again, or if a bibliography is included in the work, the note only needs to include the surname of the author, a shortened form of the title (if more than four words), and the page number(s). However, in a work that does not include a bibliography, it is recommended that the full citation be repeated when it is first used in a new chapter.
In contrast to earlier editions of CMOS, if you cite the same source two or more times consecutively, CMOS recommends using shortened citations. In a work with a bibliography, the first reference should use a shortened citation which includes the author’s name, the source title, and the page number(s), and consecutive references to the same work may omit the source title and simply include the author and page number. Although discouraged by CMOS, if you cite the same source and page number(s) from a single source two or more times consecutively, it is also possible to utilize the word “Ibid.,” ( from the Latin ibidem, which means “in the same place,”) as the corresponding note. If you use the same source but a draw from different new page, the corresponding note should use “Ibid.” followed by a comma and the new page number(s).
In the NB system, the footnote or endnote itself begins with the appropriate full-sized number, followed by a period and then a space.
In the NB system, the bibliography provides an alphabetical list of all sources used in a given work. This page, most often titled Bibliography, is usually placed at the end of the work preceding the index. It should include all sources cited within the work and may sometimes include other relevant sources that were not cited but provide further reading.
Although bibliographic entries for various sources may be formatted differently, all included sources (books, articles, websites, etc.) are arranged alphabetically by author’s last name. If no author or editor is listed, the title or, as a last resort, a descriptive phrase may be used.
Though useful, a bibliography is not required in works that provide full bibliographic information in the notes.
Common Elements
All entries in the bibliography will include the author (or editor, compiler, translator), title, and publication information.
Author Names
The author’s name is inverted in the bibliography, placing the last name first and separating the last name and first name with a comma; for example, John Smith becomes Smith, John.
Titles
Titles of books and journals are italicized. Titles of articles, chapters, poems, etc. are placed in quotation marks.
Publication Information
The year of publication is listed after the publisher or journal name.
Punctuation
In a bibliography, all major elements are separated by periods.
For more information and specific examples, see the sections on Books and Periodicals.