How to Reference Correctly (Harvard, APA and the Rest)

What actually needs a citation

The common misunderstanding is that only quotations need citing. In fact you cite whenever you use someone else's idea, argument, data, figure or finding — whether you quoted it, paraphrased it, or summarised it in a sentence.

You do not need to cite common knowledge — that water boils at 100°C at sea level — but if you learned it from a specific source and it is contestable, cite it.

The main styles and how they differ

Harvard-style systems put the author and year in the text: (Khan, 2021). APA is similar with its own precise formatting rules and is standard in psychology and the social sciences. MLA, used in humanities, uses author and page. Vancouver and IEEE use numbers referring to a numbered list.

The differences are mechanical, not intellectual. What matters is that your department has specified one and expects it applied consistently.

Consistency is what earns the marks

Most referencing marks are lost not because a student used the wrong style but because they drifted — italics on some titles, not others; some entries with a full stop, some without.

Get your department's official guide, keep it open while you write, and check your reference list against it before submitting. It is dull work worth several marks.

Build the list as you go

Writing the whole essay and then reconstructing where everything came from is how citations get lost and accidental plagiarism happens. Add the reference the moment you use the source.

Reference managers — Zotero, Mendeley, EndNote — automate the formatting and are worth the hour it takes to learn one. Always check their output, though; they make predictable errors with edited books, reports and websites.

Quoting, paraphrasing and the line to watch

Quote when the exact wording matters. Paraphrase when the idea matters more than the phrasing — but a real paraphrase rewrites the sentence structure, not just a few words. Swapping synonyms into someone else's sentence is still their sentence.

Either way, the citation is required. A close paraphrase without a citation is plagiarism even if no words are identical.

Citing awkward sources

Websites need the author or organisation, the year, the title, the URL and often an access date. Lecture slides, datasets, government reports and AI tools all have specific conventions — check your department's guide, because these are exactly where students improvise and lose marks.

If a source has no author, use the organisation. If it has no date, most styles use 'n.d.'