Sonia Ben Mokhtar Nikolaos Georgantas Valérie Issarny COCOA: COnversation-based service COmposition in pervAsive computing environments with QoS support. 1941-1955 2007 80 Journal of Systems and Software 12 http://dx.doi.org/10.1016/j.jss.2007.03.002 db/journals/jss/jss80.html#MokhtarGI07