1. Erl, T.: Service-Oriented Architecture: Concepts, Technology & Design. Prentice Hall PTR, Upper Saddle River (2005)
2. AMPLE Project: Survey of the state-of-the-art in Requirements Engineering for SPL and Model-Driven Requirements Engineering. Del. 1.1 IST - 33710 (2007)
3. Kang, K., Cohen, S., et al.: Feature-Oriented Domain Analysis (FODA) Feasibility Study. SEI, Technical Report, CMU/SEI-90-TR-021 (1990)
4. Schnieders, A., Puhlmann, F.: Variability Mechanisms in E-business Process Families. In: Proceedings of 9th International Conference on BIS, Austria (2006)