%\cite{Emma:FEL2015-WEP076}
\bibitem{Emma:FEL2015-WEP076}
    C.~Emma, K.~Fang, C.~Pellegrini, and J.~Wu,
   \textquotedblleft{Tapering Studies for TW Level X-ray FELs with a Superconducting Undulator and Built-in Focusing}\textquotedblright,
%  in \emph{Proc. FEL2015}, WEP076, pp. 726--729,
%  in \emph{Proc. FEL2015}, Daejeon, Republic of Korea, August 2015, paper WEP076, pp. 726--729,
   in \emph{Proc. 37th International Free Electron Laser Conference (FEL2015)}, Daejeon, Republic of Korea, August 2015, paper WEP076, pp. 726--729,
    ISBN: 978-3-95450-134-2,
    \url{http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/wep076.pdf},
    doi:10.18429/JACoW-FEL2015-WEP076, 2015.
