Lorenz Froihofer Johannes Osrael Karl M. Goeschka Decoupling Constraint Validation from Business Activities to Improve Dependability in Distributed Object Systems. 443-450 2007 ARES http://doi.ieeecomputersociety.org/10.1109/ARES.2007.64 conf/IEEEares/2007 db/conf/IEEEares/ares2007.html#FroihoferOG07