Bibliography management with natbib

When it comes to bibliography management in $L a T e X$ , the package natbib is a package for customising citations (especially author-year citation schemes) when using BibTeX. This article explains how to use natbib to format and cite bibliographic sources.

Note: If you are starting from scratch it's recommended to use biblatex because that package provides localization in several languages, it's actively developed and makes bibliography management easier and more flexible. However, note that most journals still use bibtex and natbib.

Introduction

A minimal working example is presented below:

\usepackage{natbib}
\bibliographystyle{unsrtnat}
\title{Bibliography management: \texttt{natbib} package}
\author{Overleaf}
\date {April 2021}

\begin{document}

\maketitle

This document is an example of \texttt{natbib} package using in bibliography
management. Three items are cited: \textit{The \LaTeX\ Companion} book 
\cite{latexcompanion}, the Einstein journal paper \cite{einstein}, and the 
Donald Knuth's website \cite{knuthwebsite}. The \LaTeX\ related items are 
\cite{latexcompanion,knuthwebsite}. 

\medskip

\bibliography{sample}

\end{document}

In this example there are four basic commands to manage the bibliography:

\usepackage{natbib}: Imports the package natbib.

\bibliographystyle{unsrtnat}: Sets the bibliography style unsrtnat. See the article about bibliography styles for more information.

\cite{labelcompanion}: Prints a reference to the citation entry, what is printed depends on the citation style. The word inside the braces corresponds to a particular entry in the bibliography file.

bibliography{sample}: Imports the file sample.bib that contains bibliography sources. See the bibliography file section.

Open an example of the natbib package in Overleaf

Basic usage

A simple working example was shown at the introduction, there are more bibliography-related commands available.

\documentclass{article}
\usepackage[english]{babel}
\usepackage[square,numbers]{natbib}
\bibliographystyle{abbrvnat}

\title{Bibliography management: \texttt{natbib} package}
\author{Overleaf}
\date {April 2021}

\begin{document}

\maketitle

This document is an example of \texttt{natbib} package using in bibliography 
management. Three items are cited: \textit{The \LaTeX\ Companion} book \cite{latexcompanion}, the Einstein journal paper \citet{einstein}, and the 
Donald Knuth's website \cite{knuthwebsite}. The \LaTeX\ related items are
\cite{latexcompanion,knuthwebsite}. 

\medskip

\bibliography{sample}

\end{document}

There are a few changes in this example:

The options square and numbers in \usepackage[square,numbers]{natbib} enable squared brackets and numeric citations respectively. See the reference guide for a list of package options

The styles abbrvnat is used here, see bibliography styles

The command \citet adds the name of the author to the citation mark, regardless of the citation style.

Open another example of the natbib package in Overleaf

The bibliography file

The bibliography files must have the standard bibtex syntax and the extension .bib. They contain a list of bibliography sources and several fields with information about each entry.

@article{einstein,
    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"
}

@misc{knuthwebsite,
    author    = "Donald Knuth",
    title     = "Knuth: Computers and Typesetting",
    url       = "http://www-cs-faculty.stanford.edu/\~{}uno/abcde.html"
}

This file contains records in a special format, for instance, the first bibliographic reference is defined by:

@article{...}: This is the first line of a record entry, @article tells BibTeX that the information stored here is about an article. The information about this entry is enclosed within braces. Besides the entry types shown in the example (article, book and misc there are a lot more, see the reference guide.

einstein: The label einstein is assigned to this entry, is a unique identifier that can be used to refer this article within the document.

author = "Albert Einstein",: This is the first field in the bibliography entry, indicates that the author of this article is Albert Einstein. Several comma-separated fields can be added using the same syntax key = value, for instance: title, pages, year, URL, etc. See the reference guide for a list of possible fields.

The information in this file can later be printed and referenced within a $L a T e X$ document, as shown in the previous sections, with the command \bibliography{sample}. Not all the information in the .bib file will be displayed, it depends on the bibliography style set in the document.

Adding the bibliography in the table of contents

If you want the bibliography to be included in the table of contents, importing the package tocbibind in the preamble will do the trick:

\documentclass{article}
\usepackage[english]{babel}

%Includes "References" in the table of contents
\usepackage[nottoc]{tocbibind}

%Import the natbib package and sets a bibliography style
\usepackage[square,numbers]{natbib}
\bibliographystyle{abbrvnat}

%Title and author
\title{Bibliography management: \texttt{natbib} package}
\author{Overleaf}
\date {April 2021}

\begin{document}

\maketitle

\tableofcontents

\section{First Section}
This document is an example...

%Imports the bibliography file "sample.bib"
\bibliography{sample}

\end{document}

Open an example of natbib and table of contents in Overleaf

Adding the line

\usepackage[nottoc]{tocbibind}

to the preamble will print the "References" or "Bibliography" in the table of contents, depending on the document type. Be careful, it will also add other elements like the Index, Glossary and list of Listings to the table of contents. For more information see the tocbibind package documentation.

Reference guide

natbib package options

round for round parentheses
square uses square brackets
curly curly braces
angle angle braces or chevrons
semicolon separates multiple citations with semicolons
colon same as semicolon
comma separate multiple citations with commas
authoryear for author-year citations
numbers for numerical citations
super superscripts for numerical citations, as in Nature
sort orders multiple citations according to the list of references
sort&compress same as sort but multiple numerical citations are compressed if possible
compress compress without sorting
longnamefirst the full name of the author will appear in the first citation of any reference
sectionbib To be used with the package chapterbib to add the bibliography to the table of contents as a unnumbered section instead of an unnumbered chapter
nonamebreak prevents hyphenation of author names
elide to omit common elements of merged references

Standard entry types

article: Article from a magazine or journal

book: A published book

booklet: A work that is printed but has no publisher or sponsoring institution

conference: An article in a conference proceedings

inbook: A part of a book (section, chapter and so on)

incollection: A part of a book having its own title

inproceedings: An article in a conference proceedings

manual: Technical documentation

mastersthesis: A Master's thesis

misc: Something that doesn't fit in any other type

phdthesis: A PhD thesis

proceedings: The same as conference

techreport: Report published by an institution

unpublished: Document not formally published, with author and title

Most common fields used in BibTeX

address	annote	author
booktitle	chaper	crossref
edition	editor	institution
journal	key	month
note	number	organization
pages	publisher	school
series	title	type
volume	year	URL
ISBN	ISSN	LCCN
abstract	keywords	price
copyright	language	contents