1. Business process execution language for web services (version 1.1). www.ibm.com/developerworks/library/specification/ws-bpel/, 2007
2. Workflow patterns;Aalst;Distributed and Parallel Databases,2003
3. Interaction categories and the foundation of typed concurrent programming;Abramsky,1994
4. Modeling and analysis of workflows using petri nets;Adam;Journal of Intelligent Information Systems,1998
5. Compositional methods for probabilistic systems;Alfaro,2001