BibTeX

The processor program works with several specific files to produce the reference list and format the citations. In the words of the program's author Oren Patashnik, the processor works as follows:^[2]

It takes as input:

1. an .aux file produced by LaTeX on an earlier run;
2. a .bst file (the style file), which specifies the general reference-list style and specifies how to format individual entries, and which is written by a style designer in a special-purpose language, and
3. .bib file(s) constituting a database of all reference-list entries the user might ever hope to use.

BibTeX chooses from the .bib file(s) only those entries specified by the .aux file (that is, those given by LaTeX's \cite or \nocite commands), and creates as output a .bbl file containing these entries together with the formatting commands specified by the .bst file. LaTeX will use the .bbl file, perhaps edited by the user, to produce the reference list.

BibTeX uses a style-independent text-based file format, a kind of flat-file database, to store bibliography items, such as articles, books, and theses. BibTeX database file names usually end in .bib. A BibTeX database file is formed by a list of entries, with each entry corresponding to a bibliographical item. Entry types correspond to various types of bibliographic sources such as article, book, or conference.

An example entry describing a mathematical handbook is structured with an entry type—here, @book—followed by a unique citation key, such as abramowitz+stegun. It also includes a list of fields, like author and title:

@book{abramowitz+stegun,
 author    = "Milton {Abramowitz} and Irene A. {Stegun}",
 title     = "Handbook of Mathematical Functions with
              Formulas, Graphs, and Mathematical Tables",
 publisher = "Dover",
 year      =  1964,
 address   = "New York City",
 edition   = "ninth Dover printing, tenth GPO printing"
}

If a document references this handbook, the bibliographic information can be formatted in different ways depending on the chosen citation style (e.g., APA, MLA, Chicago). LaTeX handles this by specifying the citation command \cite, which addresses the citation key and relies on the desired bibliography style defined in the LaTeX document.

For example, if the command \cite{abramowitz+stegun} appears in a LaTeX document, the bibtex program will include this book in the list of references and generate appropriate LaTeX formatting code. When viewing the formatted LaTeX document, the result might look like this:

Abramowitz, Milton and Irene A. Stegun (1964), Handbook of mathematical functions with formulas, graphs, and mathematical tables. New York: Dover.

Depending on the style file, BibTeX may rearrange authors' last names, change the case of titles, omit fields present in the .bib file, format text in italics, add punctuation, etc. Since the same style file is used for an entire list of references, these are all formatted consistently with minimal effort required from authors or editors.

BibTeX formats bibliographic items according to a style file, typically by generating TeX or LaTeX formatting commands, but style files can also be used to generate other types of output like HTML. BibTeX style files commonly use the file extension .bst and are written in a simple, stack-based programming language (dubbed "BibTeX Anonymous Forth-Like Language", or "BAFLL", by Drew McDermott^[10]) that describes how bibliography items should be formatted. There are some packages that can generate .bst files automatically, such as custom-bib and Bib-it.^[11][12]

Most journals or publishers that support LaTeX use a customized bibliographic style file for the convenience of the authors, often included as part of a complete LaTeX template.

• Astrophysics Data System – The NASA ADS is an online database of over eight million astronomy and physics papers and provides BibTeX format citations.
• Bebop – a web-based front-end interface for BibTeX
• BibDesk – Open-source software application for macOS for creating, editing, managing, and searching BibTeX files.
• BibSonomy – A social bookmark and publication management system based on BibTeX.
• Citavi – Reference manager. Works with various TeX-Editors and supports BibTeX input and output.
• CiteSeer – An online database of research publications which can produce BibTeX format citations.
• CiteULike (discontinued) – A community based bibliography database that had BibTeX input and output.
• The Collection of Computer Science Bibliographies – uses BibTeX as internal data format, search results and contributions primarily in BibTeX.
• Connotea – Open-source social bookmark style publication management system.
• Digital Bibliography & Library Project – A bibliography website that lists more than 910,000 articles in the computer science field.
• Google Books – The bibliographic information for each book is exportable in BibTeX format via the 'Export Citation' feature.
• Google Scholar – Google's system for searching scholarly literature provides BibTeX format citations if the option is enabled in 'Scholar Preferences'.
• Google Research – Housed within the artificial intelligence division of Google is a compilation of publications by Google staff with BibTeX citation links.
• HubMed – A versatile PubMed interface including BibTeX output.
• INSPIRE-HEP – The INSPIRE High-Energy Physics literature database provides BibTeX format citations for over one million high-energy physics papers.
• JabRef – Open-source cross-platform software application for creating, editing, managing, and searching BibTeX and BibLaTeX files.
• MathSciNet – Database by the American Mathematical Society (subscription), choose BibTeX in the "Select alternative format" box
• Mendeley – Reference manager, for collecting papers. It supports exporting collections into bib files and keep them synchronized with its own database.^[13]
• Paperpile – Reference manager, supports BibTeX input and output. BibTeX output can be customized.
• Pandoc – Open-source document converter that can read a BibTeX file and produce formatted citations in any bibliography style specified in a citation style language (CSL) file.
• Qiqqa – Software application for Windows that includes a fully featured BibTeX editor and validator, along with tools for automatically populating BibTeX records for PDFs.
• refbase – Open-source reference manager for institutional repositories and self archiving with BibTeX input and output.
• RefTeX – Emacs based reference manager.
• Wikipedia – Pressing cite this page in the Tools menu of an article provides a BibTeX format citation.
• Zentralblatt MATH – Database by the European Mathematical Society, FIZ Karlsruhe and Heidelberg Academy (subscription, 3 free entries); choose BibTeX button or format.
• Zotero – Open-source reference manager with advanced features such as synchronization between different computers, social bookmarking, searching inside saved PDFs and BibTeX output.

Data schemes

• EndNote – a text-based data scheme used by the EndNote program
• refer – an aging text-based data scheme supported on UNIX-like systems
• RIS – a text-based data scheme from Research Information Systems

Other

• Citation Style Language – a newer XML-based bibliography style specification analogous to BibTeX's .bst files but processed instead by the CiteProc program
• Comparison of reference management software
• List of TeX extensions