1. Jackson, M.: ‘Problem frames: analyzing and structuring software development problems’, (Addison Wesley Professional 2000)
2. Kande, M.: ‘A concern-oriented approach to software architecture’, 2003, PhD thesis, EPFL, Lausanne, Switzerland
3. Role-based access control models
4. The Object Management Group. ‘Unified modelling language. Version 1.5’, OMG, formal/2003-03-01, 2003