1. Can programming be liberated from the Von Neumann style? A functional style and its algebra of programs;Backus;Comm. ACM,1978
2. Algorithmische Sprache und Programmentwicklung;Bauer,1981
3. Relational algebraic semantics of functional programs;Berghammer,1985
4. Semantics of nondeterministic and noncontinuous constructs;Broy,1979
5. Distributive and modular laws in the arithmetic of relation algebras;Chin;Univ. California Publ. Math.,1951