S. McCamant, and M. Ernst. Proceedings of SAVCBS 2004: Specification and Verification of Component-Based Systems, page 47-54. Newport Beach, CA, USA), (October 2004)
W. Cook, W. Hill, and P. Canning. POPL '90: Proceedings of the 17th ACM SIGPLAN-SIGACT symposium on Principles of programming languages, page 125--135. New York, NY, USA, ACM Press, (1990)