LibGuides: A Guide to Good Referencing Skills: Citation Styles

Common Citation Styles - Overview

A citation style is a set of rules that determine how to format and organize references or citations in academic and professional writing.

Citation style varies across disciplines, and each style has its own unique set of rules for how to format in-text citations and reference lists. Ask your instructor which style s/he prefers.

Common citation styles

Citation Style	Commonly Used In	Example
APA (American Psychological Association) Latest ed.: APA 7th	Many disciplines More popular in Social Sciences	APA uses author-date system for in-text citations. In-text citation: `This study (Gates, 2022) ...` Full reference: `Gates, B. (2022). How to Prevent the Next Pandemic. Vintage.`
IEEE (Institute of Electrical and Electronics Engineers)	Engineering and Computer Science	IEEE uses a numeric system; places the numbers within square brackets. In-text citation: `This study` `[1] ...` Full reference: `[1] B. Gates, How to Prevent the Next Pandemic. Vintage, 2022.`
ACS (American Chemical Society)	Chemistry and some Science disciplines	ACS uses multiple systems: superscript numbers, numbers within paratheses, or author-year system. In-text citation: `This study¹` `...` Full reference: `(1) Gates, B. How to Prevent the Next Pandemic; Vintage, 2022.`
MLA (Modern Language Association) Latest ed.: MLA 9th	Humanities, especially Language and Literature	MLA only includes the last name of the author, placed within paratheses. In-text citation: `This study` `(Gates) ...` Full reference: `Gates, Bill. How to Prevent the Next Pandemic. Vintage, 2022.`
Chicago Manual of Style Latest ed.: Chicago 17th	Humanities (Notes-bibliography) Social, Physical, and Natural Sciences (Author-date)	Chicago uses two systems: notes-bibliography and author-date system. Notes-bibliography: In-text citation: `This study¹` `...` Footnote/Endnote: `1 Bill Gates How to Prevent the Next Pandemic (Vintage, 2022).` Full reference is needed when note does not include a full bibliography. Same format as author-date system. Author-date: (include page number in in-text) In-text citation: `This study (Gates 2022, 15) ...` Full reference: `Gates, Bill. How to Prevent the Next Pandemic. Vintage, 2022.`
Harvard	Many disciplines	Harvard uses author-year system. In-text citation: `This study (Gates, 2022) ...` Full reference: `Gates, B., 2022. How to Prevent the Next Pandemic. Vintage.`