%\cite{Mak:FEL2015-TUP002}
\bibitem{Mak:FEL2015-TUP002}
    A.~Mak, F.~Curbis, and S.~Werin,
   \textquotedblleft{Further Studies of Undulator Tapering in X-Ray FELs}\textquotedblright,
%  in \emph{Proc. FEL2015}, TUP002, pp. 321--326,
%  in \emph{Proc. FEL2015}, Daejeon, Republic of Korea, August 2015, paper TUP002, pp. 321--326,
   in \emph{Proc. 37th International Free Electron Laser Conference (FEL2015)}, Daejeon, Republic of Korea, August 2015, paper TUP002, pp. 321--326,
    ISBN: 978-3-95450-134-2,
    \url{http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/tup002.pdf},
    doi:10.18429/JACoW-FEL2015-TUP002, 2015.