Z. Huang,
   "X-Ray FEL R&D: Brighter, Better and Cheaper",
   in Proc. 37th International Free Electron Laser Conference, Daejeon, Republic of Korea, August 2015, paper MOB02, pp. 7-9,
    ISBN: 978-3-95450-134-2,
    doi:10.18429/JACoW-FEL2015-MOB02,
    http://accelconf.web.cern.ch/AccelConf/FEL2015/papers/mob02.pdf, 2015.