1. Addy EA, Simms LJ (1996) Experience report: the use of functional flows in IV&V. http://research.ivv.nasa.gov/~eaddy/funcflow
2. Andersson K (1994) Vocabulary for conceptual design. In: Proceedings of the IFIP TC5/WG5.2 workshop on formal design methods for CAD IFIP transactions B: computer applications in technology B18 p 157– 171
3. Beer S (1985) Diagnosing the system for organisations. Wiley, New york
4. Bergman B, Klefsjö B (1994) Quality: from customer needs to customer satisfaction. Studentlitteratur, Sweden, ISBN 91-44-46331-6
5. Box G, Bisgaard S, Fung C (1988) An explanation and critique of Taguchi’s contributions to quality engineering. Report No. 28, center for quality and productivity improvement, University of Wisconsin-Madison, 610 Walnut ST, Madison WI 53705 USA