Citations are composed of various combinations of basic elements of information arranged or abbreviated in certain specific ways based on the citation style. The most common citation styles are APA, MLA, and "Chicago" but there are dozens of different citation styles that have been adopted by various disciplines.
The basic elements of a citation typically include:
1. Author or authors; how many are listed varies by citation style.
2. Title of the source be it an article, book, book chapter or journal; in complete or abbreviated form based on the citation style.
3. Date of publication; year is the absolute minimum required, type of publication may necessitate month and/or day as well.
4. Page numbers are mandatory when the publication uses them.
5. Volume and issue numbers for journal or serial publications.
Other elements that are included depending on the publication type:
6. Place of publication
7. Edition
Additional elements that might be helpful to include if you're trying to be more helpful to your reader and/or are allowed to add elements to the citation style being utilized.
8. URL (uniform resource locator) or DOI (digital object identifier).
9. ISSN (International Standard Serial Number for journals/serials) or ISBN (International Standard Book Number).
10. Date accessed
