Gottesdiener, Ellen . Object-Oriented Analysis and Design Using the UML (Seminar material). EBG Consulting, Carmel, IN, 1995-2001.
Tasker, Dan . The Problem Space: Practical Techniques for Gathering and Specifying Requirements Using Objects, Events, Rules, Participants, and Locations. 1993. Published electronically; no longer available.
18.117.93.0