1. M. Bidoit, M.-C. Gaudel, and A. Mauboussin. How to make algebraic specifications more understandable? In M. Wirsing and J.A. Bergstra, editors, Algebraic Methods: Theory, Tools and Applications, number 394 in LNCS, pages 31–67. Springer-Verlag, 1989.
2. Frederick P. Brooks. No silver bullet — essence and accidents of software engineering. Computer, pages 10–19, April 1987.
3. O. Declerfayt, B. Demeuse, F. Wautier, P. Y. Schobbens, and E. Milgrom. Precise standards through formal specifications: A case study: the unix file system. In Proceedings EUUG Autumn Conference, Cascais, Portugal, 1988.
4. Kevin Lano and Howard Haughton. Specifying a concept-recognition system in Z++. In Kevin Lano and Howard Haughton, editors, Object-Oriented Specification Case Studies, chapter 7, pages 137–157. Prentice Hall, 1988.
5. Carroll Morgan and Bernard Sufrin. Specification of the UNIX Filing System. In Ian Hayes, editor, Specification Case Studies. Prentic-Hall, 1987.