1. {1} Peter Chen The Entity-Relationship Approach to Logical Data Base Design Q. E. D. Information Sciences. Wellesley. Massachusetts 1977. {1} Peter Chen The Entity-Relationship Approach to Logical Data Base Design Q. E. D. Information Sciences. Wellesley. Massachusetts 1977.
2. {2} Tom DeMarco Structured Analysis and System Specification Yourdon Press New York 1978. {2} Tom DeMarco Structured Analysis and System Specification Yourdon Press New York 1978.
3. {4} Derek Hatley and Imtiaz Pirbhai Strategies for Real-Time System Specification Dorset House New York 1988. {4} Derek Hatley and Imtiaz Pirbhai Strategies for Real-Time System Specification Dorset House New York 1988.