Citation formatting is a strange corner of academic life. The rules are precise, they differ from style to style, and they change between editions. Students lose points for a misplaced period or a missing italic, and the frustration is real because the rules feel arbitrary.

To a developer, though, a citation looks very familiar. It's structured data (author, title, year, publisher, URL) rendered through a template. Different styles are just different templates operating on the same fields. Once you see it that way, the whole thing becomes a lot less mysterious, and you can reason about it the same way you'd reason about a serializer.

This article walks through the three most common styles in US coursework (APA, MLA, and Chicago), explains where they differ and why, and builds a small TypeScript formatter so the patterns are concrete. A note on scope: style guides publish detailed edition-specific rules, and your instructor may have their own requirements.…