APA (American Psychological Association) is used primarily in social sciences and psychology — it emphasizes the date of publication because recency matters in those fields. MLA (Modern Language Association) is used in humanities and literature — it emphasizes the author and page number for in-text citations. Chicago style is used in history and some social sciences — it allows both footnote-based and author-date citation systems. Your institution or publication will specify which style to use.

A DOI (Digital Object Identifier) is a permanent alphanumeric string assigned to academic journal articles, books, and datasets to provide a stable, permanent link — unlike URLs, which change or break. If your journal article has a DOI, always include it in your citation. Most academic databases display the DOI on the article page. Format it as a URL: https://doi.org/10.xxxx/xxxxxx. APA 7th edition requires DOIs when available and makes URL optional if a DOI exists.

When no individual author is listed, use the organization or website name as the author. For example, "World Health Organization" or "National Institutes of Health." If no organization is identifiable, APA starts the citation with the article title. MLA 9 moves the title to the author position. Chicago omits the author field and starts with the title. Never fabricate an author or leave the author field blank — that creates an incomplete citation.

Use "n.d." (no date) as the year. In APA: (n.d.) appears where the year would normally go. In MLA: "n.d." appears in the date position of the citation. In Chicago: use "n.d." where the year would appear. If you can determine the approximate date from other contextual clues (like copyright notices, "last updated" notices, or Wayback Machine records), you can use that with a note that it is approximate. Always include your access date for any web source without a clear publication date.

For personal blogs and informal web content, strict adherence to a formal citation style is not required. However, you should still cite your sources — linking to the original source and attributing quotes is both ethical and good practice for SEO (outbound links to authoritative sources are a positive quality signal). If you are publishing in any academic, legal, medical, or professional context, use the appropriate formal citation format.

Et al. (Latin for "and others") is used when a work has multiple authors. In APA 7th edition, use et al. for works with 3 or more authors from the first citation. In MLA 9th edition, list up to 2 authors, then use et al. for 3 or more. In Chicago author-date, list up to 3 authors, then use et al. for 4 or more. This tool currently supports single-author citations; for multi-author works, add the et al. notation manually after generating the citation.

Legal documents use the Bluebook citation system (in the US) or jurisdiction-specific systems (OSCOLA in the UK, McGill in Canada) — not APA, MLA, or Chicago. Those legal systems have highly specific rules for citing cases, statutes, regulations, and secondary sources that differ significantly from academic citation formats. This generator is designed for academic and general writing use, not legal document preparation.