Bibliography and Citations in LaTeX

\documentclass{article}
\usepackage[
  backend=biber,        % Use biber (recommended)
  style=authoryear,     % Citation style
  sorting=nyt,          % Sort by name, year, title
  maxbibnames=10,       % Max names in bibliography
  maxcitenames=2,       % Max names in citations
  hyperref=true,        % Clickable links
  backref=true         % Back references
]{biblatex}

% Add bibliography file
\addbibresource{references.bib}

\begin{document}

\section{Introduction}
This research builds on \textcite{smith2020} and \textcite{jones2021}.
Multiple studies \parencite{brown2019,wilson2022,taylor2023} confirm...

\printbibliography

\end{document}

% In-text citations
\textcite{smith2020}           % Smith (2020) argues...
\parencite{smith2020}          % Recent studies (Smith 2020) show...
\cite{smith2020}               % Basic citation

% Multiple citations
\parencite{smith2020,jones2021,brown2019}
\textcite{smith2020,jones2021} % Smith (2020) and Jones (2021)

% Author and year separately
\citeauthor{smith2020} (\citeyear{smith2020})  % Smith (2020)
\citeauthor{smith2020}                         % Smith
\citeyear{smith2020}                           % 2020

% Page numbers and prenotes
\parencite[15]{smith2020}                      % (Smith 2020, 15)
\parencite[see][15-20]{smith2020}              % (see Smith 2020, 15-20)
\parencite[cf.][]{smith2020}                   % (cf. Smith 2020)

% Footnote citations
\footcite{smith2020}           % Footnote with full citation
\footcitetext{smith2020}       % Only footnote text

% Full citations in text
\fullcite{smith2020}           % Complete reference inline

% Journal article
@article{smith2020,
  author = {Smith, John A. and Doe, Jane B.},
  title = {Advanced Machine Learning Techniques},
  journal = {Journal of Artificial Intelligence},
  year = {2020},
  volume = {45},
  number = {3},
  pages = {123--145},
  doi = {10.1234/jai.2020.45.123},
  url = {https://example.com/article},
  abstract = {This paper presents novel approaches to...}
}

% Book
@book{jones2021,
  author = {Jones, Alice M.},
  title = {Introduction to Data Science},
  publisher = {Academic Press},
  year = {2021},
  edition = {3rd},
  address = {New York},
  isbn = {978-0123456789},
  pages = {450}
}

% Book chapter
@incollection{brown2019,
  author = {Brown, Robert C.},
  title = {Statistical Methods in Research},
  booktitle = {Handbook of Research Methods},
  editor = {Wilson, Sarah D.},
  publisher = {Scientific Publishers},
  year = {2019},
  pages = {45--67},
  address = {London}
}

% Conference paper
@inproceedings{wilson2022,
  author = {Wilson, Mark E. and Taylor, Lisa F.},
  title = {Neural Networks for Image Classification},
  booktitle = {Proceedings of the International Conference on Machine Learning},
  year = {2022},
  pages = {234--245},
  address = {Vienna, Austria},
  publisher = {PMLR},
  month = {July}
}

% PhD thesis
@phdthesis{taylor2023,
  author = {Taylor, Emma R.},
  title = {Deep Learning Applications in Computer Vision},
  school = {Massachusetts Institute of Technology},
  year = {2023},
  type = {PhD thesis},
  address = {Cambridge, MA}
}

% Online source
@online{website2024,
  author = {Organization Name},
  title = {Important Guidelines},
  url = {https://example.com/guidelines},
  urldate = {2024-01-15},
  year = {2024}
}

% Technical report
@techreport{report2023,
  author = {Research Team},
  title = {Annual Technical Report},
  institution = {National Laboratory},
  year = {2023},
  number = {TR-2023-001},
  address = {Washington, DC}
}

% Author-year styles
\usepackage[style=authoryear]{biblatex}     % (Smith 2020)
\usepackage[style=authoryear-comp]{biblatex} % (Smith 2020; Jones 2021)
\usepackage[style=apa]{biblatex}            % APA style

% Numeric styles
\usepackage[style=numeric]{biblatex}        % [1]
\usepackage[style=numeric-comp]{biblatex}   % [1-3,5]
\usepackage[style=ieee]{biblatex}           % IEEE style

% Alphabetic styles
\usepackage[style=alphabetic]{biblatex}     % [Smi20]
\usepackage[style=alphabetic-verb]{biblatex} % [Smith2020]

% Verbose styles (footnotes)
\usepackage[style=verbose]{biblatex}        % Full footnotes
\usepackage[style=verbose-ibid]{biblatex}   % With ibid.

% Field-specific styles
\usepackage[style=nature]{biblatex}         % Nature journal
\usepackage[style=science]{biblatex}        % Science journal
\usepackage[style=chicago-authordate]{biblatex} % Chicago style

% Multiple bibliographies
\begin{refsection}
\section{Chapter 1}
Citations for chapter 1 \cite{ref1,ref2}.
\printbibliography[heading=subbibliography,title={Chapter 1 References}]
\end{refsection}

\begin{refsection}
\section{Chapter 2}
Citations for chapter 2 \cite{ref3,ref4}.
\printbibliography[heading=subbibliography,title={Chapter 2 References}]
\end{refsection}

% Filtered bibliographies
\printbibliography[type=article,title={Journal Articles}]
\printbibliography[type=book,title={Books}]
\printbibliography[keyword=primary,title={Primary Sources}]
\printbibliography[nottype=online,title={Print Sources}]

% Custom categories
\DeclareBibliographyCategory{primary}
\addtocategory{primary}{smith2020,jones2021}
\printbibliography[category=primary,title={Primary Sources}]

% Split by language
\printbibliography[langid=english,title={English Sources}]
\printbibliography[langid=german,title={German Sources}]

\documentclass{article}
\usepackage{natbib} % Enhanced citation commands

\begin{document}

\section{Introduction}
\citet{smith2020} argues that machine learning...
Multiple studies \citep{jones2021,brown2019} confirm...

% Bibliography
\bibliographystyle{plainnat} % or apalike, unsrt, etc.
\bibliography{references}    % references.bib file

\end{document}

% Basic citations
\cite{smith2020}              % Smith et al. (2020) or [1]
\citep{smith2020}             % (Smith et al., 2020)
\citet{smith2020}             % Smith et al. (2020)

% Multiple citations
\citep{smith2020,jones2021}   % (Smith et al., 2020; Jones, 2021)

% Author/year separation
\citeauthor{smith2020}        % Smith et al.
\citeyear{smith2020}          % 2020

% Alternative forms
\citealp{smith2020}           % Smith et al., 2020
\citealt{smith2020}           % Smith et al. 2020

% Page numbers
\citep[p.~15]{smith2020}      % (Smith et al., 2020, p. 15)
\citep[see][pp.~10-15]{smith2020} % (see Smith et al., 2020, pp. 10-15)

% Starred versions (full author list)
\citet*{multiauthor2020}      % All authors listed
\citep*{multiauthor2020}      % All authors in parentheses

% Standard styles (without natbib)
\bibliographystyle{plain}     % Numbered, sorted alphabetically
\bibliographystyle{unsrt}     % Numbered, order of citation
\bibliographystyle{alpha}     % Alphabetic labels [Smi20]
\bibliographystyle{abbrv}     % Abbreviated names/journals

% With natbib package
\bibliographystyle{plainnat}  % Author-year, full names
\bibliographystyle{abbrvnat}  % Author-year, abbreviated
\bibliographystyle{unsrtnat}  % Author-year, citation order
\bibliographystyle{apalike}   % APA-like style

% Field-specific styles
\bibliographystyle{ieeetr}    % IEEE Transactions
\bibliographystyle{acm}       % ACM style
\bibliographystyle{amsplain}  % AMS style
\bibliographystyle{chicago}   % Chicago style

% Most reference managers can export BibTeX:

% Zotero
% 1. Select references
% 2. File → Export Library
% 3. Choose BibTeX format
% 4. Include file in LaTeX project

% Mendeley
% 1. Select references
% 2. File → Export
% 3. Choose BibTeX format

% EndNote
% 1. Select references
% 2. File → Export
% 3. Choose BibTeX format

% JabRef (dedicated BibTeX manager)
% Native BibTeX editor with LaTeX integration

% Example workflow with Zotero:
\addbibresource{zotero-export.bib} % In preamble
\cite{key-from-zotero}              % In document

% Better BibTeX for Zotero
% - Automatic citation key generation
% - Real-time sync with LaTeX projects
% - Custom key patterns

% Example citation keys:
% [auth:lower][year] → smith2020
% [authorsAlpha][year] → SJB20
% [title:clean:select,1,1][year] → Advanced2020

% In your .bib file generated by Better BibTeX:
@article{smith2020advanced,
  author = {Smith, John A.},
  title = {Advanced Machine Learning},
  journal = {AI Journal},
  year = {2020}
}

% Nature journals
\documentclass{nature}
\bibliographystyle{naturemag}

% Science
\documentclass{sciencepaper}
\bibliographystyle{Science}

% IEEE journals
\documentclass{IEEEtran}
\bibliographystyle{IEEEtran}

% ACM journals
\documentclass{acmart}
\bibliographystyle{ACM-Reference-Format}

% Elsevier journals
\documentclass{elsarticle}
\bibliographystyle{elsarticle-num}

% Springer journals
\documentclass{svjour3}
\bibliographystyle{spbasic}

% APA style (psychology)
\usepackage[style=apa]{biblatex}
\DeclareLanguageMapping{american}{american-apa}

% Chicago style (history, literature)
\usepackage[style=chicago-authordate]{biblatex}

% Split bibliographies by topic
\addbibresource{primary-sources.bib}
\addbibresource{secondary-sources.bib}
\addbibresource{methodology.bib}
\addbibresource{background.bib}

% Or use categories within one file
@article{smith2020,
  author = {Smith, John},
  title = {Primary Research},
  journal = {Main Journal},
  year = {2020},
  keywords = {primary, experimental, machine-learning}
}

% Filter by keywords
\printbibliography[keyword=primary,title={Primary Sources}]
\printbibliography[keyword=methodology,title={Methodological References}]

% Parent entry (conference proceedings)
@proceedings{conference2024,
  title = {Proceedings of the International Conference},
  year = {2024},
  editor = {Editor, Name},
  publisher = {ACM},
  address = {New York}
}

% Child entries using crossref
@inproceedings{paper1_2024,
  author = {First, Author},
  title = {First Paper Title},
  pages = {1--10},
  crossref = {conference2024}
}

@inproceedings{paper2_2024,
  author = {Second, Author},
  title = {Second Paper Title},
  pages = {11--20},
  crossref = {conference2024}
}

% The crossref field automatically inherits:
% - booktitle from title
% - publisher, year, editor, address from parent

% Define custom citation commands
\newcommand{\citepos}[1]{\citeauthor{#1}'s (\citeyear{#1})}
% Usage: \citepos{smith2020} → Smith's (2020)

\newcommand{\citeposs}[1]{\citeauthor{#1}' (\citeyear{#1})}
% For plural possessive: \citeposs{authors2020} → Authors' (2020)

% Parenthetical citations with page ranges
\newcommand{\citepp}[2]{\citep[pp.~#2]{#1}}
% Usage: \citepp{smith2020}{15-20} → (Smith 2020, pp. 15-20)

% Compare citations
\newcommand{\citecf}[1]{\citep[cf.][]{#1}}
% Usage: \citecf{smith2020} → (cf. Smith 2020)

% See also citations
\newcommand{\citesee}[1]{\citep[see][]{#1}}
% Usage: \citesee{smith2020} → (see Smith 2020)

% Anonymous authors
@article{anonymous2020,
  author = {{Anonymous}},
  title = {Confidential Research Results},
  journal = {Secret Journal},
  year = {2020}
}

% Corporate authors
@report{who2021,
  author = {{World Health Organization}},
  title = {Global Health Report 2021},
  institution = {WHO},
  year = {2021}
}

% Multiple works by same author, same year
@article{smith2020a,
  author = {Smith, John A.},
  title = {First Paper in 2020},
  journal = {Journal A},
  year = {2020}
}

@article{smith2020b,
  author = {Smith, John A.},
  title = {Second Paper in 2020},
  journal = {Journal B},
  year = {2020}
}

% Forthcoming publications
@article{jones2024,
  author = {Jones, Mary},
  title = {Future Research},
  journal = {Future Journal},
  year = {2024},
  note = {forthcoming}
}

% Customize bibliography appearance
\usepackage[
  backend=biber,
  style=authoryear,
  dashed=false,          % Repeat author names
  maxnames=3,            % Show up to 3 names before et al.
  minnames=1,            % At least 1 name before et al.
  giveninits=true,       % Use initials
  uniquename=init,       % Disambiguate by initials
  uniquelist=false,      % Don't expand name lists
  doi=true,              % Show DOIs
  isbn=false,            % Hide ISBNs
  url=false,             % Hide URLs (when DOI present)
  eprint=false           % Hide eprint info
]{biblatex}

% Customize field formats
\DeclareFieldFormat{title}{\mkbibemph{#1}} % Italicize titles
\DeclareFieldFormat[article]{title}{\mkbibquote{#1}} % Quote article titles
\DeclareFieldFormat{journaltitle}{\textit{#1}} % Italicize journal names
\DeclareFieldFormat{doi}{%
  \mkbibacro{DOI}\addcolon\space
  \href{https://doi.org/#1}{\nolinkurl{#1}}}

% Remove "In:" before journal names
\renewbibmacro{in:}{%
  \ifentrytype{article}{}{
    \printtext{\bibstring{in}\intitlepunct}}}

% Custom name format
\DeclareNameAlias{sortname}{family-given}
\DeclareNameAlias{default}{family-given}

% Define a new entry type for preprints
\DeclareBibliographyDriver{preprint}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/translator+others}%
  \setunit{\printdelim{nametitledelim}}\newblock
  \usebibmacro{title}%
  \newunit\newblock
  \printfield{howpublished}%
  \newunit\newblock
  \printfield{note}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

% Use in .bib file
@preprint{arxiv2024,
  author = {Researcher, Name},
  title = {Preprint Title},
  year = {2024},
  eprint = {2401.12345},
  eprinttype = {arXiv},
  eprintclass = {cs.LG}
}

% Numbered bibliography with custom labels
\defbibenvironment{bibliography}
  {\enumerate
     {\setlength{\leftmargin}{\bibhang}%
      \setlength{\itemindent}{-\leftmargin}%
      \setlength{\itemsep}{\bibitemsep}%
      \setlength{\parsep}{\bibparsep}}}
  {\endenumerate}
  {\item[\printfield{labelnumber}.]}  % Add period after number

% Custom bibliography heading
\defbibheading{bibliography}[\bibname]{%
  \section*{#1}%
  \markboth{#1}{#1}%
  \addcontentsline{toc}{section}{#1}}

% Split bibliography by decade
\defbibcheck{2020s}{\iffieldint{year}
  {\ifnumless{\thefield{year}}{2020}
    {\skipentry}{\ifnumgreater{\thefield{year}}{2029}
      {\skipentry}{}}}}
  {\skipentry}}

\defbibcheck{2010s}{\iffieldint{year}
  {\ifnumless{\thefield{year}}{2010}
    {\skipentry}{\ifnumgreater{\thefield{year}}{2019}
      {\skipentry}{}}}}
  {\skipentry}}

% Print by decade
\printbibliography[check=2020s,title={2020s Publications}]
\printbibliography[check=2010s,title={2010s Publications}]

% Multi-volume book set
@mvbook{encyclopedia2024,
  author = {Editor, Chief},
  title = {Encyclopedia of Computer Science},
  year = {2024},
  volumes = {5},
  publisher = {Academic Press}
}

% Individual volume
@book{encyclopedia2024_vol2,
  author = {Editor, Chief},
  title = {Encyclopedia of Computer Science},
  year = {2024},
  volume = {2},
  maintitle = {Encyclopedia of Computer Science},
  mainsubtitle = {Complete Edition},
  publisher = {Academic Press}
}

% Reference within multi-volume work
@inbook{smith2024_encyclopedia,
  author = {Smith, John},
  title = {Machine Learning Fundamentals},
  booktitle = {Encyclopedia of Computer Science},
  year = {2024},
  volume = {3},
  pages = {234--267},
  publisher = {Academic Press},
  crossref = {encyclopedia2024}
}

% Legal citation package
\usepackage[style=apa]{biblatex}

% Case law
@legal{brown1954,
  title = {Brown v. Board of Education},
  year = {1954},
  volume = {347},
  reporter = {U.S.},
  pages = {483},
  court = {Supreme Court}
}

% Statute
@legislation{ada1990,
  title = {Americans with Disabilities Act},
  year = {1990},
  volume = {42},
  section = {12101},
  code = {U.S.C.}
}

% Custom legal citation format
\DeclareFieldFormat[legal]{title}{\textit{#1}}
\DeclareBibliographyDriver{legal}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \printfield{title}%
  \setunit{\addcomma\space}%
  \printfield{volume}%
  \setunit{\space}%
  \printfield{reporter}%
  \setunit{\space}%
  \printfield{pages}%
  \setunit{\space}%
  \mkbibparens{\printfield{year}}%
  \usebibmacro{finentry}}

% Annotated bibliography
@article{smith2020,
  author = {Smith, John},
  title = {Important Study},
  journal = {Key Journal},
  year = {2020},
  annotation = {This seminal work established the foundation
                for modern approaches to the problem. The author
                uses innovative methodology to demonstrate...}
}

% Print with annotations
\renewbibmacro*{finentry}{%
  \finentrypunct
  \iffieldundef{annotation}
    {}
    {\par\vspace{0.5\baselineskip}%
     \begin{quotation}\small
       \printfield{annotation}%
     \end{quotation}}%
  \finentry}

% In-text annotation references
\newcommand{\citenote}[2]{%
  \cite{#1}\footnote{#2}}

% Usage: \citenote{smith2020}{This study is particularly
% relevant because it addresses our specific use case.}

% Good citation key patterns
@article{smith2020ml,          % author + year + topic
  author = {Smith, John},
  title = {Machine Learning Advances},
  year = {2020}
}

@book{johnson2021deeplearning, % author + year + keywords
  author = {Johnson, Mary},
  title = {Deep Learning Fundamentals},
  year = {2021}
}

@inproceedings{lee2024cvpr,    % author + year + venue
  author = {Lee, David},
  title = {Computer Vision Paper},
  booktitle = {CVPR},
  year = {2024}
}

% Avoid these patterns
@article{1,                    % Too generic
@article{ml_paper,             % No year/author info
@article{my_favorite_paper,    % Personal references
@article{temp,                 % Temporary names

% Using refsection (BibLaTeX)
\documentclass{book}
\usepackage[style=authoryear,refsection=chapter]{biblatex}
\addbibresource{references.bib}

\begin{document}

\chapter{Introduction}
\begin{refsection}
Content with citations \cite{ref1,ref2}.
\printbibliography[heading=subbibliography]
\end{refsection}

\chapter{Methods}
\begin{refsection}
More content \cite{ref3,ref4}.
\printbibliography[heading=subbibliography]
\end{refsection}

% Global bibliography at end
\printbibliography[title={Complete Bibliography}]
\end{document}

% Categorize references by topic
\DeclareBibliographyCategory{theory}
\DeclareBibliographyCategory{experiments}
\DeclareBibliographyCategory{applications}

% Assign categories
\addtocategory{theory}{einstein1905,bohr1913}
\addtocategory{experiments}{miller2020,jones2021}
\addtocategory{applications}{smith2022,brown2023}

% Print categorized bibliographies
\printbibheading{\section{References by Topic}}

\printbibliography[
  category=theory,
  title={Theoretical Foundations}]

\printbibliography[
  category=experiments,
  title={Experimental Studies}]

\printbibliography[
  category=applications,
  title={Practical Applications}]

% Or filter by keywords in .bib entries
\printbibliography[
  keyword={machine-learning},
  title={Machine Learning References}]

% Setup hyperref with biblatex
\usepackage{hyperref}
\hypersetup{
  colorlinks=true,
  citecolor=blue,
  linkcolor=blue,
  urlcolor=blue
}

% Custom link colors for different citation types
\DeclareFieldFormat{citehyperref}{%
  \DeclareFieldAlias{bibhyperref}{noformat}%
  \bibhyperref{#1}}

\DeclareFieldFormat{textcitehyperref}{%
  \DeclareFieldAlias{bibhyperref}{noformat}%
  \bibhyperref{\textcolor{green}{#1}}}

% Backref - show where each reference is cited
\usepackage[style=authoryear,backref=true]{biblatex}

% Custom backref text
\DefineBibliographyStrings{english}{%
  backrefpage = {cited on page},
  backrefpages = {cited on pages}
}

% Add bibliography to TOC
\printbibliography[heading=bibintoc,title={References}]

% Or manually
\printbibliography
\addcontentsline{toc}{chapter}{Bibliography}

% For numbered sections
\printbibliography[heading=bibnumbered]

% Custom heading with TOC
\defbibheading{custom}[\bibname]{%
  \chapter*{#1}%
  \markboth{#1}{#1}%
  \addcontentsline{toc}{chapter}{#1}%
  \vspace{2em}%
  \center\textit{All sources have been carefully verified.}%
  \vspace{1em}}

\printbibliography[heading=custom]

% Using glossaries package with citations
\usepackage{glossaries}
\makeglossaries

% Define term with citation
\newglossaryentry{machinelearning}{
  name={machine learning},
  description={A subset of artificial intelligence
    that enables systems to learn from data
    \cite{mitchell1997}}
}

% In text
The concept of \gls{machinelearning} has evolved
significantly since its inception.

% Print glossary with citations
\printglossary[title={Glossary with References}]