2Hollingsworth D. The workflow reference model. Workflow Management Coalition. 1995.
3Fan YS. Foundation of Workflow Management Technique. Beijing: Tsinghua University Press; Springer-Verlag, 2001 (in Chinese).
4Rumbaugh J, Jacobson I, Booch G. The Unified Modeling Language Reference Manual. Addison Wesley Longman, Inc., 1999.
5Kopoulos D G,Hornick M,Sheth A. An Overview of workflow management: From process modeling to workflow automation infrastructure. Distributed and Parallel Databases, 1995,119 - 153.