1. A Discipline of Programming;Dijkstra,1976
2. Monadic computation and iterative algebraic theories;Elgot,1975
3. Matricial theories;Elgot;J. Algebra,1976
4. M. Hennessy, “The Semantics of Call-by-Value and Call-by-Name in a Nondeterministic Environment,” Tech. Report CS-77-13, Univ. of Waterloo.
5. The semantics of nondeterminism;Hennessy,1976