B.~Lorbeer, N.~Baboi, L.P.~Petrosyan, and F.~Schmidt-Föhre, "Design, Development and Commissioning of a MTCA-Based Button and Strip-Line BPM System for FLASH2", in Proc. 3rd International Beam Instrumentation Conference, Monterey, CA, USA, paper TUPF08, pp. 320–323, ISBN: 978-3-95450-141-0, \url{http://jacow.org/IBIC2014/papers/tupf08.pdf}, 2014.