Bibliography and Citations¶

LaTeX makes referencing and formatting bibliographies powerful and automatic.

BibTeX: The classic approach.
BibLaTeX: The modern, feature-rich replacement.

1. BibTeX¶

Creating a Database (`.bib` file)¶

Create a file like references.bib and add entries:

@article{einstein1905,
    author  = "Albert Einstein",
    title   = "{Zur Elektrodynamik bewegter K{\"o}rper}. ({German})
               [{On} the electrodynamics of moving bodies]",
    journal = "Annalen der Physik",
    volume  = "322",
    number  = "10",
    pages   = "891--921",
    year    = "1905",
    doi     = "http://dx.doi.org/10.1002/andp.19053221004"
}

@book{latexcompanion,
    author    = "Michel Goossens and Frank Mittelbach and Alexander Samarin",
    title     = "The \LaTeX\ Companion",
    year      = "1993",
    publisher = "Addison-Wesley",
    address   = "Reading, Massachusetts"
}

In Your Document¶

Linking the .bib file:

\documentclass{article}

\begin{document}

Einstein's theory of relativity \cite{einstein1905} revolutionized physics.
The \LaTeX\ Companion \cite{latexcompanion} is an essential book.

\bibliographystyle{plain} % plain, unsrt, alpha, abbrv
\bibliography{references} % filename without .bib

\end{document}

Compilation Order¶

pdflatex mydoc.tex (Creates .aux)
bibtex mydoc (Creates .bbl)
pdflatex mydoc.tex (Merges .bbl)
pdflatex mydoc.tex (Updates references)

2. BibLaTeX (Recommended)¶

BibLaTeX is easier to customize and handles complex citations better.

Preamble setup¶

\usepackage[style=authoryear, backend=biber]{biblatex}
\addbibresource{references.bib}

style=ieee, apa, mla, authoryear, numeric.
backend=biber: Biber is the default engine for BibLaTeX (replace bibtex step with biber).

Printing the Bibliography¶

Place \printbibliography where you want the references to appear.

\printbibliography[heading=bibintoc, title={References}]

3. In-Text Citation Commands¶

Modern packages like biblatex and natbib provide specific commands for different citation styles.

BibLaTeX Citation Table¶

Command	Description	Output (authoryear)	Output (numeric)
`\cite{key}`	Basic citation	Einstein 1905	[1]
`\parencite{key}`	In parentheses	(Einstein, 1905)	[1]
`\textcite{key}`	Narrative (author in text)	Einstein (1905)	Einstein [1]
`\autocite{key}`	Context-sensitive	(Einstein, 1905)	[1]
`\footcite{key}`	Citation in footnote	Citation in footer	¹
`\citeauthor{key}`	Author name only	Einstein	Einstein
`\citeyear{key}`	Year only	1905	1905
`\nocite{key}`	Add to bib without citing	(No output)	(No output)

Natbib Equivalence Table¶

If you are using the natbib package, use these commands:

Natbib Command	BibLaTeX Equivalent	Purpose	Example
`\citet{key}`	`\textcite{key}`	Narrative citation	Einstein (1905)
`\citep{key}`	`\parencite{key}`	Parenthetical citation	(Einstein, 1905)
`\citet*{key}`	N/A	Full author list	Einstein, Podolsky, & Rosen (1935)

Practical Usage Example¶

Here is how you might use these commands in a research paper:

LaTeX Source:

In the field of physics, \textcite{einstein1905} introduced the revolutionary 
concept of special relativity. This work remains a cornerstone of modern 
science \parencite{einstein1905}. Later, developers like \citeauthor{knuth1984} 
focused on the presentation of such ideas through software, specifically in 
his work during \citeyear{knuth1984}. General guides such as \autocite{latexcompanion} 
provide further technical depth. For more info, see the project docs \footcite{mkdocs}.

Rendered Output (Author-Year):

In the field of physics, Einstein (1905) introduced the revolutionary concept of special relativity. This work remains a cornerstone of modern science (Einstein, 1905). Later, developers like Knuth focused on the presentation of such ideas through software, specifically in his work during 1984. General guides such as (Goossens et al., 1993) provide further technical depth. For more info, see the project docs ¹.

Author Variations (Single, Two, 3+)¶

How citations look depends on the number of authors in the .bib entry:

Author Count	Example `author` field	`\textcite` Output	`\parencite` Output
1 Author	`Albert Einstein`	Einstein (1905)	(Einstein, 1905)
2 Authors	`Jane Doe and John Smith`	Doe and Smith (2024)	(Doe and Smith, 2024)
3+ Authors	`Alice Alpha and Bob Beta and others`	Alpha et al. (2025)	(Alpha et al., 2025)

👋 Note: The use of "et al." for 3 or more authors is automatic in styles like authoryear or apa.

Natbib (Alternative)¶

Often used in sciences for author-year citations (\citep, \citet). Compatible with BibTeX styles.

\usepackage{natbib}
\bibliographystyle{plainnat}

4. Troubleshooting: "Not Reflecting"¶

If your citations or bibliography are not appearing:

Check Compilation Order:
- For BibTeX: pdflatex → bibtex → pdflatex → pdflatex.
- For BibLaTeX: pdflatex → biber → pdflatex.
Verify File Names: Ensure \bibliography{filename} or \addbibresource{filename.bib} exactly matches your .bib file name.
Check Keys: Ensure the key in \cite{key} exactly matches the key in the @entry{key, ...} in your .bib file.
Auxiliary Files: Sometimes old .aux or .bbl files cause issues. Try deleting them and re-compiling.