1. Lubars M Potts C, Richter C. A review of the state of the practice in requirements modelling. In IEEE International Symposium on Requirements Engineering. IEEE Computer Society Press, Washington, DC 1993
2. Gilb T. Principles of software engineering management. Addison-Wesley, Reading, MA, 1986
3. Hawryszkiewycz IT. Introduction to systems analysis and design. Prentice-Hall, Englewood Cliffs, NJ, 1988
4. Sneed H. Software engineering management. Ellis Horwood, Chichester, 1989
5. Flynn DJ. Information systems requirements: determination and analysis. McGraw-Hill, New York, 1992