Tommaso Bolognesi A Conceptual Framework for State-Based and Event-Based Formal Behavioural Specification Languages. 107-116 2004 conf/iceccs/2004 ICECCS http://csdl.computer.org/comp/proceedings/iceccs/2004/2109/00/21090107abs.htm db/conf/iceccs/iceccs2004.html#Bolognesi04