%\cite{Li:FEL2015-TUC02}
\bibitem{Li:FEL2015-TUC02}
    R.K.~Li,
   \textquotedblleft{Ultra-Low Charge, Ultra-High Brightness Frontiers of Photoinjectors: Challenges and Perspectives}\textquotedblright,
%  presented at FEL2015, Daejeon, Republic of Korea, August 2015, paper TUC02, unpublished.
   presented at the 37th International Free Electron Laser Conference (FEL2015), Daejeon, Republic of Korea, August 2015, paper TUC02, unpublished.