bibliography — biblatex+biber and natbib+bibtex

This suite supports both stacks equally. The first action is always: detect what the document uses.

Detect the active stack

# biblatex+biber if either is present:
grep -E '\\usepackage(\[[^\]]*\])?\{biblatex\}' main.tex
grep -E '\\addbibresource' main.tex

# natbib+bibtex if these are present and biblatex is not:
grep -E '\\usepackage(\[[^\]]*\])?\{natbib\}' main.tex
grep -E '\\bibliographystyle\{' main.tex
grep -E '\\bibliography\{' main.tex

If both biblatex and natbib are loaded, that's a bug — they conflict. Stop and report.

If neither is loaded but the document has \cite{...} calls, the user is using LaTeX's built-in thebibliography env or the document is broken.

biblatex + biber (recommended for new work)

Setup

\usepackage[backend=biber, style=authoryear-comp, sorting=nyt, maxcitenames=2]{biblatex}
\addbibresource{refs.bib}                  % NOTE: WITH .bib extension
% In body:
As shown by \textcite{einstein1905}, ...
\parencite{wallace1905}                    % "(Wallace, 1905)"
\printbibliography

Compile order: pdflatex → biber → pdflatex → pdflatex. Latexmk handles automatically.

Built-in biblatex styles

Discipline-specific styles (load matching package)

• IEEE: \usepackage[backend=biber, style=ieee]{biblatex} + biblatex-ieee package.
• APA 7: \usepackage[backend=biber, style=apa]{biblatex} + biblatex-apa.
• Chicago author-date: \usepackage[backend=biber, style=chicago-authordate]{biblatex} + biblatex-chicago.
• Chicago notes-bib: style=chicago-notes.
• Nature: style=nature + biblatex-nature.
• ACS (chemistry): \usepackage[style=chem-acs]{biblatex} + biblatex-chem.

Citation commands

Common errors

• Empty bibliography — ran bibtex when biber expected. Check <main>.bcf exists (biber) vs <main>.aux only (bibtex). Latexmk normally picks correctly.
• Package biblatex Warning: Please rerun LaTeX after biber — needs another pdflatex pass. Latexmk auto-handles.
• Mixing \bibliography{refs} (legacy) with biblatex causes silent miscompiles. Use \addbibresource{refs.bib} only.

Sources: https://ctan.org/pkg/biblatex, https://github.com/plk/biblatex.

natbib + bibtex (legacy and many journal templates)

Setup

\usepackage[round, authoryear]{natbib}    % options: round|square, authoryear|numbers
% In body:
\citet{einstein1905}                       % "Einstein (1905)"  textual
\citep{einstein1905}                       % "(Einstein, 1905)" parenthetical
% Bibliography:
\bibliographystyle{plainnat}               % no .bst extension
\bibliography{refs}                        % no .bib extension

Compile order: pdflatex → bibtex → pdflatex → pdflatex. Latexmk handles automatically.

Standard natbib styles

plainnat, abbrvnat, unsrtnat. Plus discipline-specific: agsm (Harvard), apalike, chicago, dinat.

Journal-required styles (often natbib-mandated)

When a journal class loads natbib and provides a .bst, do not switch to biblatex. Switching breaks submission.

Citation commands (natbib)

Common errors

• I couldn't open database file refs.bib.bib — passed refs.bib to \bibliography{}; pass basename refs only.
• Citation appears as [?] — bibtex didn't run, or the key isn't in any .bib. Run bibtex <main> and check output.
• Loading natbib AFTER hyperref breaks citation links — natbib must be loaded first.
• Non-ASCII in .bib may corrupt silently — use {\"o}, \'e escapes for bibtex; or migrate to biblatex+biber.

Sources: https://ctan.org/pkg/natbib.

.bib file hygiene

Whichever stack:

• Use stable, lowercase, hyphen-separated keys: einstein1905-relativity, not Einstein 05 or MyKey42.
• One reference per record. Required fields per type per BibTeX spec (@article needs author, title, journal, year; etc.).
• For DOI: doi = {10.1234/abc} (no URL prefix; biblatex/natbib add it).
• For multi-author last names with prefixes ("van der Waals"), use {van der Waals} to keep them grouped, or split with family=Waals, prefix=van der.

Migrating natbib → biblatex (or vice versa)

When a paper changes target journal:

1. Confirm the new template's required stack (read the journal's author-instructions PDF — delegate to /academic-latex:docs-lookup).
2. Remove the old stack's preamble lines and bibliography commands.
3. Add the new stack's preamble.
4. Rewrite citation commands per the mapping table:

1. Replace \bibliography{refs} + \bibliographystyle{...} with \addbibresource{refs.bib} + biblatex's style= option.
2. Recompile. Confirm output looks right.

Mass-rewrite with care — sed -i on \citet→\textcite is OK only if you've reviewed the .tex first; some \citet calls may need \textcite while others want \citeauthor.

When uncertain

For style-specific options (e.g., "does biblatex-apa support et-al-min=3 for 7th edition?") delegate to /academic-latex:docs-lookup. For journal templates, fetch the journal's author-instructions PDF before assuming a stack.

Last verified

2026-05-09 — biblatex v3.21 (2025-07-10), natbib v8.31b, biber, plk/biblatex on GitHub.