@inbook{Date2002b,
author = {Date, C.J. and Darwen, H. and Lorentzos, N.A.},
title= {Chapter 12: Integrity Constrains II: General Constraints},
year = {2002b},
booktitle = {Temporal Data and the Relational Model},
address = {San Francisco},
publisher = {Morgan Kaufmann},
pages = {213--244},
}