E. Salehi, B. Maraghechi, and N.S. Mirian,
   "Three-dimensional Simulation of a Harmonic Lasing Free-Electron Laser Amplifier",
   in Proc. 37th International Free Electron Laser Conference, Daejeon, Republic of Korea, August 2015, paper MOP075, pp. 213-216,
    ISBN: 978-3-95450-134-2,
    doi:10.18429/JACoW-FEL2015-MOP075,
    http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/mop075.pdf, 2015.