1. Garvin, D.A.: Building a Learning Organization. In: Harward Business Review on Knowledge Management, pp. 47–80. Harward Business School Press, Boston (1998)
2. Basili, V.R., Caldiera, G., Rombach, H.D.: Experience Factory. In: Marciniak, J.J. (ed.) Encyclopaedia of Software Engineering. John Wiley & Sons, Inc., Hoboken (2002)
3. Denzin, N.K., Lincoln, Y.S.: Handbook of Qualitative Research. Sage Publications, London (1994)
4. Creswell, J.W.: Research Design, Qualitative and Quantitative Approaches. Sage Publications, Thousand Oaks (1994)
5. Fenton, N., Pfleeger, S.L.: Software Metrics: A Rigorous & Practical Approach, 2nd edn. International Thomson Computer Press (1996)