\documentclass{article}
\usepackage{amssymb,amsmath}
\usepackage[mathletters]{ucs}
\usepackage[utf8x]{inputenc}
\usepackage{natbib}
\bibliographystyle{plainnat}
\usepackage[breaklinks=true,unicode=true,pdfborder={0 0 0}]{hyperref}
% avoid problems with \sout in headers with hyperref:
\pdfstringdefDisableCommands{\renewcommand{\sout}{}}
\setlength{\parindent}{0pt}
\setlength{\parskip}{6pt plus 2pt minus 1pt}
\setcounter{secnumdepth}{0}


\begin{document}

\section{Pandoc with citeproc-hs}

\begin{itemize}
\item
  {[}@nonexistent{]}
\item
  @nonexistent
\item
  \citet{item1} says blah.
\item
  \citet[p.~30]{item1} says blah.
\item
  \citet[p.~30, with suffix]{item1} says blah.
\item
  \citeauthor{item1} \citetext{\citeyear{item1}; \citeyear[p.~30]{item2}; \citealp[see also][]{item3}} says blah.
\item
  In a note.\footnote{A citation without locators \citep{item3}.}
\item
  A citation group \citetext{\citealp[see][p.~34--35]{item1}; \citealp[also][chap. 3]{item3}}.
\item
  Another one \citep[see][p.~34--35]{item1}.
\item
  And another one in a note.\footnote{Some citations \citetext{\citealp[see][chap. 3]{item2}; \citealp{item3}; \citealp{item1}}.}
\item
  Citation with a suffix and locator \citep[pp.~33, 35--37, and nowhere else]{item1}.
\item
  Citation with suffix only \citep[and nowhere else]{item1}.
\item
  Now some modifiers.\footnote{Like a citation without author: \citeyearpar{item1}, and now Doe with a locator \citeyearpar[p.~44]{item2}.}
\item
  With some markup \citep[\emph{see}][p. \textbf{32}]{item1}.
\end{itemize}
\renewcommand\refname{References}
\bibliography{biblio}

\end{document}