Kais Klai Samir Tata Jörg Desel Symbolic Abstraction and Deadlock-Freeness Verification of Inter-enterprise Processes. 294-309 2009 BPM http://dx.doi.org/10.1007/978-3-642-03848-8_20 conf/bpm/2009 db/conf/bpm/bpm2009.html#KlaiTD09