1. An introduction to relational analysis for data-base design;Addis,1977
2. Theories of Abstract Automata;Arbib,1969
3. How a computer should think;Belnap,1976
4. Infinite valued logic as a basis for set theory;Chans,1964
5. A relational model of data for large shared data banks;Codd;Communications of the ACM,1970