Bernhard K. Aichernig Bernhard Peischl Martin Weiglhofer Franz Wotawa Protocol Conformance Testing a SIP Registrar: an Industrial Application of Formal Methods. 215-226 2007 conf/sefm/2007 SEFM http://doi.ieeecomputersociety.org/10.1109/SEFM.2007.31 db/conf/sefm/sefm2007.html#AichernigPWW07