Author year citation

You need to include your biblography file as follows:

\bibliography{yourBibtexFile} 
\bibliographystyle{apalike} %or any other style you like

And then cite your reference using \cite{hermanss2012}

See the example below:

\documentclass[11pt,a4paper]{article}

\begin{document}
\noindent This is the place for the abstract\cite{hermanns2012}

\bibliography{test}           % Or whatever path and filename your bibtex is located
\bibliographystyle{apalike}   % Or any other style you like

\end{document}