Alexander A. Letichevsky Julia V. Kapitonova Vsevolod Kotlyarov Vladislav A. Volkov A. A. Letichevsky Jr. Thomas Weigert Semantics of Message Sequence Charts. 117-132 2005 conf/sdl/2005 SDL Forum http://dx.doi.org/10.1007/11506843_8 db/conf/sdl/sdl2005.html#LetichevskyKKVLW05