A. Novokhatski, F.-J. Decker, Y. Nosochkov, and M.K. Sullivan,
   "The Effect of Wakefields on the FEL Performance",
   in Proc. 37th International Free Electron Laser Conference, Daejeon, Republic of Korea, August 2015, paper MOP055, pp. 161-165,
    ISBN: 978-3-95450-134-2,
    doi:10.18429/JACoW-FEL2015-MOP055,
    http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/mop055.pdf, 2015.