Citation Styles Explained: APA vs MLA vs IEEE vs Chicago

Citation styles exist so readers can find your sources and judge your evidence. The style you use is usually decided by your field or your target journal — not by you. Here is how the four most common differ.

APA (social sciences, education, psychology)

Author–date in the text: (Smith, 2023). Emphasises the year because recency matters in these fields. Reference list alphabetical by author.

MLA (humanities, literature, languages)

Author–page in the text: (Smith 45). Emphasises the page so readers can find the exact passage in a text being analysed. "Works Cited" list.

IEEE (engineering, computer science)

Numbered in order of appearance: [1], [2]. Compact and unobtrusive, which suits technical writing dense with references. The list is numbered, not alphabetical.

Chicago (history, some humanities)

Two systems: notes-bibliography (footnotes) and author-date. Flexible and detailed; common in history and publishing.

The golden rule

Pick the one your department or journal requires, then be perfectly consistent. Tools can format references for you, but you remain responsible for accuracy.

How ProSearch helps

ProSearch exports your sources ready-to-use: BibTeX and RIS for Zotero/Mendeley/EndNote, and clean IEEE-formatted reference lists in its reports — so the formatting is done and you can switch styles in your reference manager.