Søren Brandt and Jørgen Lindskov Knudsen. "Generalising the BETA type system" pp421--448

Cointe, P. (1996) Cointe, P. editor, Proceedings of the Ninth European Conference on Object-Oriented Programming (ECOOP), July 1996. LNCS 1098, Springer-Verlag  

Languages mentioned BETA {1975} Object oriented language