1. Lecture Notes in Computer Science;M. Abadi,1997
2. Lecture Notes in Computer Science;A.J. Alencar,1991
3. Back, R., Mikhajlov, L., von Wright, J.: Formal semantics of inheritance and object substitutability. Technical Report 337, Turku Centre for Computer Science, Lemminkäisenkatu 14, FIN-20520, Turku, Finland (2000)
4. Back, R., Mikhajlova, A., von Wright, J.: Class refinement as semantics of correct object substitutability. Technical Report 333, Turku Centre for Computer Science, Lemminkäisenkatu 14, FIN-20520, Turku, Finland (2000)
5. Back, R., von Wright, J.: Refinement Calculus. A Systematic Introduction. Graduate Texts in Computer Science. Springer-Verlag (1998)