@inproceedings(
MitchVis96,author="Mitchell, J.C. and Viswanathan,  R.", 
	Title="Effective models of polymorphism, subtyping and recursion",
	Booktitle="23rd International Colloquium on Automata,
Languages, and Programming",
	Year="1996",
	Publisher="Springer LNCS ???",
	pages="??")