%\cite{Mirian:FEL2015-MOP070} \bibitem{Mirian:FEL2015-MOP070} N.S.~Mirian, \textquotedblleft{Harmonic Generation in Two Orthogonal Undulators}\textquotedblright, % in \emph{Proc. FEL2015}, MOP070, pp. 200--204, % in \emph{Proc. FEL2015}, Daejeon, Republic of Korea, August 2015, paper MOP070, pp. 200--204, in \emph{Proc. 37th International Free Electron Laser Conference (FEL2015)}, Daejeon, Republic of Korea, August 2015, paper MOP070, pp. 200--204, ISBN: 978-3-95450-134-2, \url{http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/mop070.pdf}, doi:10.18429/JACoW-FEL2015-MOP070, 2015.