1. Abran, A., Bourque, P., Dupuis, R., Moore, J.W., Tripp, L.L.: Guide to the Software Engineering Body of Knowledge - SWEBOK. IEEE Press (2004)
2. Adrion, W.R., Branstad, M.A., Cherniavsky, J.C.: Validation, verification, and testing of computer software. CSUR 1982 14(2), 159–192 (1982)
3. Alrajeh, D., Kramer, J., Russo, A., Uchitel, S.: Learning operational requirements from goal models. In: ICSE 2009, pp. 265–275. IEEE Computer Society (2009)
4. Anton, A.I.: Goal-based requirements analysis. In: Proc. of the Second Int. Conf. on Requirements Engineering, pp. 136–144 (1996)
5. Boehm, B.W.: Verifying and validating software requirements and design specifications. IEEE Software 1(1), 75–88 (1984)