S.R. Marques \emph{et al.},
   "Status of the Sirius RF BPM Electronics",
   in Proc. 3rd International Beam Instrumentation Conference, Monterey, CA, USA, paper WECYB3, pp. 505–509,
    ISBN: 978-3-95450-141-0,
    \url{http://jacow.org/IBIC2014/papers/wecyb3.pdf},
    2014.