1. Barringer, H., Kuiper, R. & Pnueli, A. (1985). Now you may compose temporal logic specifications. ACMSymposium on the m o r y of Computing, 51-63, New York: ACM.
2. Bastide, R. & Palanque, P. (1990). Petri Net objects for the design, validation and prototyping of user-driven interfaces. Roceedings of Znteract'90, 625-631. North Holland: Elsevier.
3. Chan, T. (1994). A graphical tool to support the QOC notation. Master's thesis, Department of Computer Science, University of York, United Kingdom.
4. Clark, K. L. (1981). Tlic s y W i s and ver#htian of logic progwmr (Tech. Rep. No. 81/36). London: Imperial College of Science and Technology, Department of Computing.