Advanced Object Technology

Abadi, Martin and Cardelli, Luca. A Theory of Objects. Monographs in Computer Science, David Gries and Fred B. Schneider (Eds) Springer-Verlag,1996. (best conceptual overview of basic object constructs followed by indepth theoretical analyis of object systems)

Meyer, Bertrand. Object-Oriented Software Construction. Prentice Hall, April 1997 (An encyclopedic overview of object technology by an original in the field. Thoroughly revised and updated.)