1. H. Padamsee, J. Knobloch, and T. Hays, RF Superconductivity for Accelerators (Wiley-VCH, New York, 2008), pp. 3–36.
2. The European x-ray free-electron laser, Technical Design Report No. DESY 2006-097, 2007, http://xfel.eu/en/documents.
3. ILC Technical Design Report, June2013, www.linearcollider.org.