\errorcontextlines=10
\documentclass[pdftex]{article}
\usepackage{times,url}
\usepackage{natbib}
\bibliographystyle{agu}
\usepackage[debug,colorlinks,backref]{hyperref}
\begin{document}
\title{Another test}
\author{Sergey Lesenko}
\maketitle

\section{Introduction}
(PDF), described in
\cite{Adobe,Deutsch}, and also available from
\TeX{} $\longrightarrow$ DVIPS\cite{Rokicki} 
GhostScript\cite{Deutsch}
TeX2PDF\cite{Sojka}
\cite{Haralambous:TB16-2-162}.  We may compare this route with that

\citeyear{Adobe}, and also available from
\TeX{} $\longrightarrow$ DVIPS\citeyear{Rokicki} 
GhostScript\citeyear{Deutsch}
TeX2PDF\citeyear{Sojka}
\citeyear{Haralambous:TB16-2-162}.  We may compare this route with that

\citeauthor{Adobe}, and also available from
\TeX{} $\longrightarrow$ DVIPS\citeauthor{Rokicki} 
GhostScript\citeauthor{Deutsch}
TeX2PDF\citeauthor{Sojka}
\citeauthor{Haralambous:TB16-2-162}.  We may compare this route with that

\citefullauthor{Adobe}, and also available from
\TeX{} $\longrightarrow$ DVIPS\citefullauthor{Rokicki} 
GhostScript\citefullauthor{Deutsch}
TeX2PDF\citefullauthor{Sojka}
\citefullauthor{Haralambous:TB16-2-162}.  We may compare this route with that

\citet{Adobe}, and also available from
\TeX{} $\longrightarrow$ DVIPS\citet{Rokicki} 
GhostScript\citet{Deutsch}
TeX2PDF\citet{Sojka}
\citet{Haralambous:TB16-2-162}.  We may compare this route with that

\citealt{Adobe}, and also available from
\TeX{} $\longrightarrow$ DVIPS\citealt{Rokicki} 
GhostScript\citealt{Deutsch}
TeX2PDF\citealt{Sojka}
\citealt{Haralambous:TB16-2-162}.  We may compare this route with that

\cite*{Adobe}, and also available from
\TeX{} $\longrightarrow$ DVIPS\cite*{Rokicki} 
GhostScript\cite*{Deutsch}
TeX2PDF\cite*{Sojka}
\cite*{Haralambous:TB16-2-162}.  We may compare this route with that

\bibliography{testbib}
\end{document}