Machine Learning for Software Reuse. - Walter L. Hill (IJCAI, 1987)

F-Bounded Polymorphism for Object-Oriented Programming. - Peter S. Canning; William R. Cook; Walter L. Hill; Walter G. Olthoff; John C. Mitchell (FPCA, 1989)

Interfaces for Strongly-Typed Object-Oriented Programming. - Peter S. Canning; William R. Cook; Walter L. Hill; Walter G. Olthoff (OOPSLA, 1989)

Inheritance Is Not Subtyping. - William R. Cook; Walter L. Hill; Peter S. Canning (POPL, 1990)