@inbook{Date2002a,
author = {Date, C.J. and Darwen, H. and Lorentzos, N.A.},
title= {Chapter 11: Integrity Constraints I: Candidate Keys and Related Constraints},
year = {2002a},
booktitle = {Temporal Data and the Relational Model},
address = {San Francisco},
publisher = {Morgan Kaufmann},
pages = {187--212},
}