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How to Add Citations and References in LaTeX with BibTeX

LetX Team

To add citations in LaTeX, store your references in a .bib file, cite them in your text with \cite{key}, and print the bibliography with \bibliography{yourfile}. BibTeX then formats and orders your entire reference list automatically. You can do all of this — including the extra compile passes — without any local setup in LetX.

Managing references by hand is a nightmare: renumbering, reformatting, and matching styles wastes hours. BibTeX solves this completely. Write each reference once, cite it anywhere, and let LaTeX handle the rest.

1. Create a .bib File

Make a file called references.bib and add entries. Each entry has a type, a citation key, and fields:

@article{smith2025,
  author  = {Smith, Jane and Doe, John},
  title   = {A Study of Everything},
  journal = {Journal of Important Results},
  year    = {2025},
  volume  = {12},
  pages   = {45--67}
}
 
@book{knuth1984,
  author    = {Knuth, Donald E.},
  title     = {The TeXbook},
  publisher = {Addison-Wesley},
  year      = {1984}
}

The key (smith2025) is how you'll refer to each source in your document.

2. Cite in Your Text

Reference any entry by its key:

The results were significant \cite{smith2025}.
 
This builds on foundational work \cite{knuth1984, smith2025}.

3. Print the Bibliography

At the end of your document, choose a style and point to your .bib file:

\bibliographystyle{plain}   % or 'ieeetr', 'apalike', 'unsrt'
\bibliography{references}

BibTeX generates a formatted, correctly ordered reference list — and renumbers everything if you add or remove a citation.

Compile order matters

BibTeX requires multiple passes: LaTeX → BibTeX → LaTeX → LaTeX. Miss a pass and you'll see [?] where citation numbers should be. Editors like LetX run the full sequence automatically, so your citations always resolve.

Using natbib for Author-Year Styles

For author-year citations like (Smith, 2025), load natbib:

\usepackage{natbib}
% ...
\citet{smith2025}   % Smith (2025)
\citep{smith2025}   % (Smith, 2025)
 
\bibliographystyle{plainnat}
\bibliography{references}

The Modern Approach: BibLaTeX

biblatex with the biber backend is the modern, more flexible option, with better Unicode support and easier customization:

\usepackage[style=authoryear, backend=biber]{biblatex}
\addbibresource{references.bib}
% ...
\cite{smith2025}
% at the end:
\printbibliography

Common Citation Problems

  • Citations show as [?] — you missed a BibTeX/biber pass, or the key is misspelled.
  • Undefined control sequence — you used a natbib command like \citet without loading natbib.
  • References not appearing — make sure the entry is actually cited, or use \nocite{*} to include everything.
Let the editor handle the pipeline

Getting the BibTeX pipeline right locally is fiddly. In LetX the compile chain is automatic — you just cite and your bibliography appears.

Get It Working in Seconds

Citations are one of LaTeX's biggest advantages over word processors — once they're set up, they maintain themselves. The fastest way to see it working is a preconfigured cloud editor.

Try BibTeX citations for free at LetX.app.

Frequently Asked Questions