1. Mylopoulos, J.: Conceptual modelling and telos. In: Conceptual Modeling, Databases, and Case: An Integrated View of Information Systems Development (1992)
2. Gurr, C.: Effective diagrammatic communication: Syntactic, semantic and pragmatic issues. Journal of Visual Languages & Computing 10(4), 317–342 (1999)
3. Lecture Notes in Computer Science;D. Birkmeier,2010
4. Beck, K., Beedle, M., van Bennekum, A., Cockburn, A., Cunningham, W., Fowler, M., Grenning, J., Highsmith, J., Hunt, A., Jeffries, R., Kern, J., Marick, B., Martin, R.C., Mellor, S., Schwaber, K., Sutherland, J., Thomas, D.: Manifesto for agile software development (2001)
5. Boehm, B., Basili, V.R.: Software defect reduction top 10 list. Computer 34(1), 135–137 (2001)