Intermediate 35 min read

LaTeX Citation Styles Guide

Master all major citation styles in LaTeX for academic writing. This comprehensive guide covers APA 7th edition, IEEE, Harvard, Chicago, MLA, Vancouver, and more. Learn how to implement each style using BibTeX and BibLaTeX with 50+ practical examples, formatting rules, and discipline-specific guidelines for papers, theses, and publications.

Introduction to Citation Styles

Citation styles are standardized formats for acknowledging sources in academic writing. Different disciplines prefer different styles, and understanding how to implement them correctly in LaTeX is essential for professional publications, theses, and research papers.

Why Citation Styles Matter

Proper citation styles ensure academic integrity, enable readers to locate sources, provide credit to original authors, follow discipline conventions, and meet publication requirements. Many journals require specific styles for submission.

Style Categories

Category Styles Citation Format Common in
Author-Year APA, Harvard, Chicago Author-Date (Smith, 2020) Social sciences, humanities
Numeric IEEE, Vancouver, Nature [1], [2] Engineering, medicine, sciences
Note-Based Chicago Notes, Oxford Footnotes/endnotes History, literature
Alphabetic Alpha, abbreviated [Smi20] Mathematics, computer science

APA Style (7th Edition)

APA (American Psychological Association) style is widely used in psychology, education, and social sciences. The 7th edition introduced several changes including simplified formatting and better guidance for online sources.

Setup

APA Style Setup
% BibLaTeX (Recommended)
\usepackage[style=apa, backend=biber]{biblatex}
\DeclareLanguageMapping{english}{english-apa}
\addbibresource{references.bib}

% Compile with: pdflatex → biber → pdflatex → pdflatex

% Traditional BibTeX (limited support)
\usepackage{apacite}
\bibliographystyle{apacite}

In-Text Citations

APA Citation Examples
% Narrative citation (author part of sentence)
\textcite{smith2020}
% Output: Smith (2020)

% Parenthetical citation
\parencite{smith2020}
% Output: (Smith, 2020)

% Multiple authors
\textcite{smith2020}      % Smith and Jones (2020)
\textcite{multiple2020}   % Smith et al. (2020) - 3+ authors

% Multiple works
\parencite{smith2020, jones2019}
% Output: (Jones, 2019; Smith, 2020)

% Page numbers
\parencite[p. 15]{smith2020}
% Output: (Smith, 2020, p. 15)

% Secondary source
\parencite[as cited in][]{jones2020}
% Output: (as cited in Jones, 2020)

Reference List Entry Examples

APA .bib Entries
% Journal article
@article{smith2020,
  author = {Smith, John A. and Jones, Mary B.},
  title = {The Effects of Climate Change},
  journal = {Environmental Psychology},
  year = {2020},
  volume = {45},
  number = {3},
  pages = {123--145},
  doi = {10.1037/env0000123}
}

% Book
@book{johnson2019,
  author = {Johnson, Robert},
  title = {Cognitive Psychology},
  subtitle = {An Introduction},
  edition = {3},
  year = {2019},
  publisher = {Academic Press},
  location = {New York, NY}
}

% Chapter in edited book
@incollection{brown2021,
  author = {Brown, Lisa},
  title = {Memory Systems},
  booktitle = {Handbook of Cognition},
  editor = {Davis, Peter},
  year = {2021},
  pages = {45--67},
  publisher = {Oxford University Press},
  location = {Oxford, UK}
}

% Website
@online{who2020,
  author = {{World Health Organization}},
  title = {Mental Health and COVID-19},
  year = {2020},
  url = {https://www.who.int/mental-health},
  urldate = {2021-03-15}
}
💡 APA 7 Tip: DOIs are preferred over URLs. Use up to 20 authors in references (then "et al."). Online sources need retrieval dates only if content may change.

IEEE Style

IEEE (Institute of Electrical and Electronics Engineers) style uses numeric citations and is standard in engineering, computer science, and technology fields.

Setup

IEEE Style Setup
% BibLaTeX (Recommended)
\usepackage[style=ieee, backend=biber]{biblatex}
\addbibresource{references.bib}

% Traditional BibTeX
\bibliographystyle{IEEEtran}

% For IEEEtran document class
\documentclass{IEEEtran}
\bibliographystyle{IEEEtran}

Citation Format

IEEE Citation Examples
% Basic citation
\cite{smith2020}
% Output: [1]

% Multiple citations
\cite{smith2020, jones2019, brown2021}
% Output: [1]–[3] or [1], [2], [3]

% Citation ranges (with cite package)
\usepackage{cite}
\cite{ref1, ref2, ref3, ref4}
% Output: [1]–[4]

% In text
As shown in \cite{smith2020}, the method...
% Output: As shown in [1], the method...

According to Smith \cite{smith2020}...
% Output: According to Smith [1]...

Reference Examples

IEEE .bib Entries
% Journal article
@article{smith2020,
  author = {J. Smith and M. Jones},
  title = {Deep Learning for Image Recognition},
  journal = {IEEE Trans. Pattern Anal. Mach. Intell.},
  volume = {42},
  number = {5},
  pages = {1234--1245},
  month = may,
  year = {2020},
  doi = {10.1109/TPAMI.2020.1234567}
}

% Conference paper
@inproceedings{brown2021,
  author = {L. Brown and K. Davis},
  title = {Efficient Neural Networks},
  booktitle = {Proc. IEEE Int. Conf. Computer Vision (ICCV)},
  year = {2021},
  pages = {100--108},
  address = {Montreal, QC, Canada},
  month = oct
}

% Book
@book{johnson2019,
  author = {R. Johnson},
  title = {Digital Signal Processing},
  edition = {4th},
  publisher = {Prentice Hall},
  address = {Upper Saddle River, NJ},
  year = {2019}
}

% Standard
@techreport{ieee802,
  author = {{IEEE}},
  title = {802.11ax-2021 - {IEEE} Standard for Wireless {LAN}},
  institution = {IEEE},
  year = {2021},
  type = {Standard}
}
IEEE Style Rules

Use author initials only (J. Smith, not John Smith). Abbreviate journal names. List all authors (no "et al." in references). Month abbreviations: jan, feb, mar, etc.

Harvard Referencing

Harvard is a generic author-year style widely used in UK universities and various disciplines. Note that "Harvard" isn't a single standard—many variations exist.

Setup

Harvard Style Setup
% BibLaTeX (Harvard authoryear)
\usepackage[style=authoryear, backend=biber]{biblatex}
\addbibresource{references.bib}

% Traditional BibTeX
\usepackage{natbib}
\bibliographystyle{agsm}  % Australian Government Style Manual
% or: plainnat, abbrvnat

% Harvard package (another option)
\usepackage{harvard}
\bibliographystyle{agsm}

Citation Examples

Harvard Citations
% Using BibLaTeX
\textcite{smith2020}           % Smith (2020)
\parencite{smith2020}          % (Smith 2020)
\parencite{smith2020, jones2019}  % (Jones 2019; Smith 2020)

% Using natbib
\citet{smith2020}              % Smith (2020)
\citep{smith2020}              % (Smith 2020)
\citep[p. 25]{smith2020}       % (Smith 2020, p. 25)

% Multiple authors
\citet{twoauthors}             % Smith and Jones (2020)
\citet{threeauthors}           % Smith, Jones and Brown (2020)
\citet{fourauthors}            % Smith et al. (2020)

% Year only
\citeyear{smith2020}           % 2020

% Author only
\citeauthor{smith2020}         % Smith

Reference Format

Harvard Reference Examples
% Output format: Author, A. (Year) Title. Location: Publisher.

% Book
@book{smith2020,
  author = {Smith, John},
  title = {Research Methods in Psychology},
  year = {2020},
  publisher = {McGraw-Hill},
  address = {London}
}

% Journal article
@article{jones2019,
  author = {Jones, Mary and Brown, Robert},
  title = {Climate change adaptation},
  journal = {Environmental Research},
  year = {2019},
  volume = {120},
  number = {4},
  pages = {450--475}
}

% Website
@online{bbc2021,
  author = {{BBC News}},
  title = {UK economy recovery},
  year = {2021},
  url = {https://www.bbc.co.uk/news/business},
  urldate = {2021-06-15}
}

Chicago Manual of Style

Chicago style offers two systems: author-date (common in sciences) and notes-bibliography (common in humanities).

Setup

Chicago Style Setup
% BibLaTeX - Author-Date System
\usepackage[style=chicago-authordate, backend=biber]{biblatex}
\addbibresource{references.bib}

% BibLaTeX - Notes System
\usepackage[style=chicago-notes, backend=biber]{biblatex}
\addbibresource{references.bib}

% Traditional BibTeX
\bibliographystyle{chicago}  % Author-date
\bibliographystyle{chicagoa} % Annotated

Author-Date Citations

Chicago Author-Date
% In-text citations
\textcite{smith2020}           % Smith 2020
\parencite{smith2020}          % (Smith 2020)
\parencite[25]{smith2020}      % (Smith 2020, 25)
\parencite[chap. 3]{smith2020} % (Smith 2020, chap. 3)

% Multiple works
\parencite{smith2020; jones2019}
% Output: (Jones 2019; Smith 2020)

% Same author, different years
\parencite{smith2019, smith2020}
% Output: (Smith 2019, 2020)

Notes System

Chicago Notes
% Footnote citations
\footcite{smith2020}
% First citation: full reference in footnote
% Subsequent: shortened form

% Custom footnote
According to recent research\footcite[25]{smith2020}, 
the results show...

% Endnote version
\usepackage{endnotes}
\endnotecite{smith2020}

Bibliography Entries

Chicago .bib Format
% Book
@book{smith2020,
  author = {Smith, John},
  title = {The History of Science},
  year = {2020},
  publisher = {University of Chicago Press},
  address = {Chicago}
}

% Journal article
@article{jones2019,
  author = {Jones, Mary},
  title = {Climate Policy Analysis},
  journal = {Journal of Environmental Studies},
  year = {2019},
  volume = {45},
  number = {2},
  pages = {123--145}
}

% Chapter in edited volume
@incollection{brown2021,
  author = {Brown, Robert},
  title = {Modern Architecture},
  booktitle = {Twentieth-Century Design},
  editor = {Davis, Sarah},
  year = {2021},
  pages = {67--89},
  publisher = {Yale University Press},
  address = {New Haven}
}

MLA Style (9th Edition)

MLA (Modern Language Association) style is standard in literature, languages, and humanities. The 9th edition emphasizes flexible guidelines and universal elements.

Setup

MLA Style Setup
% BibLaTeX MLA
\usepackage[style=mla, backend=biber]{biblatex}
\addbibresource{references.bib}

% Traditional BibTeX (limited)
\bibliographystyle{mla}

% Manual formatting often needed for MLA
\usepackage{mla13}  % MLA 8th/9th edition package

Parenthetical Citations

MLA Citations
% Basic citation (author last name and page)
\parencite[25]{smith}
% Output: (Smith 25)

% Author in text
According to Smith, the analysis shows \parencite[25]{smith}
% Output: According to Smith, the analysis shows (25).

% No author (use shortened title)
\parencite["Climate Crisis" 15]{}
% Output: ("Climate Crisis" 15)

% Multiple authors
\parencite[Smith and Jones 30]{}
% Output: (Smith and Jones 30)

% Three or more authors
\parencite[Smith et al. 45]{}
% Output: (Smith et al. 45)

% Multiple works
\parencite[Smith 25; Jones 30]{}
% Output: (Smith 25; Jones 30)

Works Cited Format

MLA Bibliography Entries
% Book
@book{smith,
  author = {Smith, John},
  title = {The Modern Novel},
  publisher = {Penguin},
  year = {2020},
  address = {New York}
}
% Output: Smith, John. The Modern Novel. Penguin, 2020.

% Journal article
@article{jones,
  author = {Jones, Mary},
  title = {Postmodern Poetry},
  journal = {American Literature},
  volume = {95},
  number = {3},
  year = {2019},
  pages = {450--475}
}
% Output: Jones, Mary. "Postmodern Poetry." 
%         American Literature, vol. 95, no. 3, 2019, pp. 450-75.

% Website
@online{bbc,
  author = {{BBC}},
  title = {UK Literature Survey},
  year = {2021},
  url = {https://www.bbc.co.uk/literature},
  urldate = {2021-06-15}
}
% Output: BBC. "UK Literature Survey." 2021,
%         www.bbc.co.uk/literature. Accessed 15 June 2021.
MLA 9th Edition Changes

Simplified container system, flexible date formats, removal of "Web" medium, inclusion of URLs/DOIs, and emphasis on core elements that apply universally across source types.

Vancouver Style

Vancouver style is a numeric system widely used in medical and scientific journals. Developed by the International Committee of Medical Journal Editors (ICMJE).

Setup

Vancouver Style Setup
% BibLaTeX Vancouver
\usepackage[style=vancouver, backend=biber]{biblatex}
\addbibresource{references.bib}

% Traditional BibTeX
\bibliographystyle{vancouver}

% Nature variant
\bibliographystyle{naturemag}

Citation Format

Vancouver Citations
% Basic citation
Studies have shown \cite{smith2020} that...
% Output: Studies have shown (1) that...
% or: Studies have shown [1] that...

% Multiple citations
Research \cite{smith2020, jones2019, brown2021} indicates...
% Output: Research (1-3) indicates...

% Superscript format (common variant)
\usepackage[super]{natbib}
Studies have shown\cite{smith2020} that...
% Output: Studies have shown¹ that...

Reference Examples

Vancouver References
% Journal article
@article{smith2020,
  author = {Smith J and Jones M and Brown R},
  title = {Treatment outcomes in clinical trials},
  journal = {Lancet},
  year = {2020},
  volume = {395},
  number = {10225},
  pages = {685--91}
}
% Output: Smith J, Jones M, Brown R. Treatment outcomes 
%         in clinical trials. Lancet. 2020;395(10225):685-91.

% Book
@book{johnson2019,
  author = {Johnson R},
  title = {Medical biochemistry},
  edition = {5},
  publisher = {Elsevier},
  address = {Amsterdam},
  year = {2019}
}
% Output: Johnson R. Medical biochemistry. 5th ed. 
%         Amsterdam: Elsevier; 2019.

% Chapter
@incollection{davis2021,
  author = {Davis P},
  title = {Cardiac physiology},
  booktitle = {Textbook of medicine},
  editor = {Wilson K},
  edition = {3},
  publisher = {McGraw-Hill},
  address = {New York},
  year = {2021},
  pages = {125--45}
}
% Output: Davis P. Cardiac physiology. In: Wilson K, editor.
%         Textbook of medicine. 3rd ed. New York: McGraw-Hill;
%         2021. p. 125-45.

Other Numeric Styles

Nature Style

Nature Journal Style
% BibLaTeX
\usepackage[style=nature, backend=biber]{biblatex}

% Traditional
\bibliographystyle{naturemag}

% Citations: superscript numbers
Recent work\cite{smith2020} shows...
% Output: Recent work¹ shows...

Science Style

Science Journal Style
% BibLaTeX
\usepackage[style=science, backend=biber]{biblatex}

% Traditional
\bibliographystyle{science}

Other Author-Year Styles

Authoryear-icomp

Compact Author-Year
% Compact inline citations
\usepackage[style=authoryear-icomp]{biblatex}

% Multiple same-author citations compressed
\parencite{smith2018, smith2019, smith2020}
% Output: (Smith 2018, 2019, 2020)

Alphabetic Style

Alphabetic Labels
% Author initials + year
\usepackage[style=alphabetic]{biblatex}

\cite{smith2020}
% Output: [Smi20]

\cite{smith2020, jones2019}
% Output: [Jon19, Smi20]

Choosing the Right Style

Discipline/Field Recommended Style Alternative
Psychology, Education APA Harvard
Engineering, Computer Science IEEE Numeric
Medicine, Healthcare Vancouver AMA
History, Philosophy Chicago Notes Oxford
Literature, Languages MLA Chicago
Business, Economics Harvard, APA Chicago Author-Date
Natural Sciences Nature, Science Vancouver
Mathematics Alphabetic Numeric
⚠️ Always Check Journal Guidelines Different journals within the same field may require different styles. Always consult the specific journal's author guidelines before submission.

Customizing Styles

Modifying Existing Styles

Style Modifications
% Change max author names
\usepackage[maxbibnames=10, maxcitenames=2]{biblatex}

% Remove DOI/URL/ISBN
\usepackage[doi=false, url=false, isbn=false]{biblatex}

% Add DOI as hyperlink
\usepackage[doi=true]{biblatex}
\DeclareFieldFormat{doi}{%
  \mkbibacro{DOI}\addcolon\space
  \ifhyperref
    {\href{https://doi.org/#1}{\nolinkurl{#1}}}
    {\nolinkurl{#1}}}

% Custom sorting
\usepackage[sorting=ydnt]{biblatex}  % Year descending

Frequently Asked Questions

Which citation style should I use for my paper?

Choose based on: (1) Your academic discipline's conventions, (2) Your institution's requirements, (3) Journal submission guidelines if applicable, (4) Instructor preferences for coursework. When in doubt, ask your supervisor or check the target publication's author guidelines.

Can I switch citation styles easily?

Yes, with BibLaTeX! Just change the style= option and recompile. Your .bib file stays the same. With traditional BibTeX, change \bibliographystyle{}. Some minor adjustments may be needed for optimal formatting.

What's the difference between APA and Harvard?

APA is a specific standard with detailed rules (7th edition). Harvard is a generic author-year format with many variants—different universities have different "Harvard" rules. APA is more prescriptive; Harvard is more flexible.

Should I use BibTeX or BibLaTeX for citation styles?

BibLaTeX is recommended for modern documents. It offers better style support, Unicode handling, and customization. Use BibTeX only if required by a journal or for compatibility with legacy documents.

How do I cite sources not covered by standard entry types?

Use the most similar entry type and add custom fields. BibLaTeX's @online handles most web sources. For unusual sources, consider @misc with detailed fields or check style-specific guidance.

Where can I find official style guides?

APA: Publication Manual of the APA (7th ed.)
IEEE: IEEE Editorial Style Manual
Chicago: Chicago Manual of Style (17th ed.)
MLA: MLA Handbook (9th ed.)
Vancouver: ICMJE Recommendations
Most have online versions or institutional subscriptions available.