Relational database writings, 1985-1989 - C. J. Date - Google Books

http://books.google.de/books?id=19BQAAAAMAAJ&q=inauthor:%22Andrew+Warden%22&dq=inauthor:%22Andrew+Warden%22&hl=de&sa=X&ei=Ac6CT5

Collected papers--many of them previously unpublished, on various aspects of relational technology--include such topics as the problems of duplicates, foreign keys, database integrity, distributed database systems, and tips on SQL.