References:
G. M. Nijssen and Terry Halpin, Conceptual Schema and Relational Database Design, (Prentice Hall, Sydney:1989).
Your author is grateful to Mr. Halpin for providing information to supplement his book, and for his comments and suggestions about this article. Any remaining errors, however, are your author's, not his. [NOTE: Since this was written, he has published a 2nd edition of this book.] |