Cohn, M. (2006) Agile Estimating and Planning USA: Robert C. Martin Series, Prentice Hall
Martin, R. C., Martin, M. (2007) Agile Principles, Patterns and Practices in C# USA: Robert C. Martin Series, Prentice Hall.
Ambler, S. (2002) Agile Modeling: Effective Practices for eXtreme Programming and the Unified Process USA: John Wiley & Sons
Dennis, A., Wixom, B. A., Tegarden, D. (2007) Systems analysis and design with UML Version 2.0 : an object-oriented approach (3rd ed.) USA: John Wiley & Sons