Guide
Referencing styles compared: APA, MLA, Chicago, OSCOLA and Bluebook
What each major style is used for, how its citations work, and how to choose and apply one without losing marks to inconsistency.
Two families of style
Almost every referencing style belongs to one of two families. Author-date styles put a short citation in the text, such as an author's name and a year, and give full details in a reference list. Note styles put a number in the text and the citation in a footnote. Legal styles are note styles with their own rules for cases and legislation.
The five styles at a glance
| Style | Published by | Mainly used in | In-text form | List at the end |
|---|---|---|---|---|
| APA | American Psychological Association | Psychology, education, social sciences | Author and year | References |
| MLA | Modern Language Association | Literature, languages, humanities | Author and page | Works Cited |
| Chicago | University of Chicago Press | History, humanities; some sciences | Footnotes, or author and date | Bibliography or reference list |
| OSCOLA | Oxford Law Faculty | Law, in the UK and beyond | Footnotes | Tables of cases and legislation; bibliography |
| Bluebook | Law reviews of Columbia, Harvard, Pennsylvania and Yale | Law, mainly in the United States | Footnotes in academic writing | Usually none; full citations in notes |
Current editions
Editions change, and the rules change with them. When this guide was written in November 2026, the publishers' own sites listed the MLA Handbook in its ninth edition, The Chicago Manual of Style in its 18th edition, OSCOLA in its 5th edition and The Bluebook in its 22nd edition. Confirm the edition your institution requires on the official sites listed below; some universities continue to require an earlier edition for a time.
How the same source looks
The differences are easiest to see with one journal article cited in each family.
- Author-date (in text): a bracketed author and year, with a page number for a quotation.
- Author-page (in text): a bracketed author and page, with no year.
- Note: a superscript number, and a footnote that gives the author, title, journal, volume, year and page.
Within a family, styles still differ on the order of elements, punctuation, italics, capitalisation of titles, and how many authors are named before "et al.". These small rules are where most errors occur, so copy the pattern from the official guide, not from another paper.
Choosing a style
- Check your university's thesis regulations or your journal's author guidelines. If they name a style, use it.
- If a house template or style guide exists, it takes priority over the general manual.
- If you have a free choice, use the style most common in your discipline and in the journals you cite.
Applying it consistently
- Enter every source in a reference manager when you first read it, with complete details.
- Record page numbers with every note and quotation.
- Check that each in-text citation has an entry in the list, and each entry is cited.
- Check author names, years and titles against the source itself, not against another paper's reference list.
- Do a final pass on punctuation and italics for each source type: book, chapter, article, case, statute, website.
Official sources
APA Style · MLA Style Center · The Chicago Manual of Style · OSCOLA, Oxford Law Faculty · The Bluebook
Common questions
Which referencing style should I use?
The one your university, department or target journal prescribes. If you have a choice, use the style most common in your discipline. Never mix styles in one document.
Do reference managers get the formatting right?
Mostly, but not always. Tools such as Zotero, Mendeley and EndNote depend on the data you enter, and output styles can lag behind a new edition. Check the final reference list against the official guide.
Does it matter which edition of a style I follow?
Yes. Rules change between editions. Check which edition your institution or journal expects, and follow that one throughout.
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