1. Allen J.F., “Maintaining knowledge about temporal intervals”, Communications of the ACM, 26:832–843, 1983.
2. Alonso G., Hagen C.,“Workflow Concepts for Spatial Processes, SSD’97.
3. Alonso G., Mohan C., “ WFMS: the next generation of distibuted processing tools”, In Advanced Transaction Models and Architectures, 1997.
4. P.C. Attie, M.P. Singh, A.P. Sheth, and M. Rusinkiewicz, “Specifying and Enforching Intertask Dependencies” VLDB, 1993
5. Mohan C. “Tutorial:State of the Art in Workflow Management Systems Research and Products”, DASFAA’ 97, Australia.