%\cite{Stupakov:FEL2015-MOC01}
\bibitem{Stupakov:FEL2015-MOC01}
    G.~Stupakov,
   \textquotedblleft{Using Pipe With Corrugated Walls for a Sub-Terahertz FEL}\textquotedblright,
%  presented at FEL2015, Daejeon, Republic of Korea, August 2015, paper MOC01, unpublished.
   presented at the 37th International Free Electron Laser Conference (FEL2015), Daejeon, Republic of Korea, August 2015, paper MOC01, unpublished.