1. Modelling the interplay of conflicting goals with use and misuse cases;Alexander,2002
2. Component Based Development for Enterprise Systems;Allen,1998
3. Schaum's Outline of UML;Bennett,2001
4. Systems Thinking, Systems Practice;Checkland,1981
5. Department of Health, National Service Framework for Older People, http://www.doh.gov.uk/, 2001.