%\cite{Viefhaus:FEL2015-WED02}
\bibitem{Viefhaus:FEL2015-WED02}
    J.~Viefhaus,
   \textquotedblleft{An Online Diagnostic Unit for FEL Photon Parameter Determination and Optimization}\textquotedblright,
%  presented at FEL2015, Daejeon, Republic of Korea, August 2015, paper WED02, unpublished.
   presented at the 37th International Free Electron Laser Conference (FEL2015), Daejeon, Republic of Korea, August 2015, paper WED02, unpublished.