Grady Booch Robert A. Maksimchuk Michael W. Engle Bobbi J. Young Jim Connallen Kelli A. Houston Object-oriented analysis and design with applications, third edition. 2008 33 ACM SIGSOFT Software Engineering Notes 5 http://doi.acm.org/10.1145/1402521.1413138 db/journals/sigsoft/sigsoft33.html#BoochMEYCH08