1. Lecture Notes in Computer Science;A. Ankolekar,2002
2. Hamadi, R., Benatallah, B.: A Petri Net-based Model for Web Service Composition. In: Proceedings of ADC 2003, Workshop on Planning for Web Services, pp. 191–200 (2003)
3. Tang, Y., Chen, L., He, K.-T., Jing, N.: SRN: An Extended Petri-Net-Based Workflow Model for Web Service Composition. In: Proceedings of ICWS 2004, pp. 591–599 (2004)
4. Andrews, T., Curbera, F., Dholakia, H., et al.: Specification: Business Process Execution Language for Web Services Version 1.1. Web of IBM Corporation (2003),
http://www.ibm.com/developerworks/library/ws-bpel
5. McCarthy, D.R., Dayal, U.: The Architecture of An Active Database Management System. In: Proc. ACM-SIGMOD 1989 Int’l Conf. Management of Data, Portland, Oregon, pp. 215–224 (1989)