1. S. Abiteboul and P.C. Kanellakis, Object identity as a query language primitive. Proc. ACM SIGMOD Int. Conf., Portland, Oregon, 1989, 1159–173.
2. M. Atkinson et al. The object-oriented database system manifesto, in 1st Int’l Conf. on Deductive and Object Oriented Databases. W. Kim, J-M. Nicolas, S. Nishio (eds), 1989, 370–395
3. F. Bancilhon Object-oriented database systems, Proc. 7th PODS, 1988, pp. 152–162.
4. C. Beeri. A Formal approach to object-oriented databases. Data and Knowledge Engineering 5,(1990), 353–382. A preliminary version in 1st Intl Conf. on Deductive and Object Oriented Databases. W. Kim, J-M. Nicolas, S. Nishio (eds), 1989, 370–395
5. C. Beeri and B. Thalheim, Can I see your identification, please? — Identification is well-founded in object-oriented databases, manuscript, Dec. 1992.