M.M.~Dehler, S.~Hunziker, and M.~Leich,
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   in Proc. 3rd International Beam Instrumentation Conference, Monterey, CA, USA, paper WEPD10, pp. 660–664,
    ISBN: 978-3-95450-141-0,
    \url{http://jacow.org/IBIC2014/papers/wepd10.pdf},
    2014.