1. Diophantine correct non-standard models in the isols;Nerode;Ann. of Math.,1966
2. L. S. Hay, Topics in recursion theory: I. The co-simple isols, II. Creative sets, Doctoral Thesis, Cornell University, 1965
3. Recursive equivalence types;Dekker;Univ. California Publ. Math. (N.S.),1960
4. Recursive equivalence types and combinatorial functions (Part 1);Myhill;Bull. Amer. Math. Soc.,1958
5. J. Myhill, Recursive equivalence types and combinatorial functions (Part 2), Proc. Int. Congress in Logic, Methodology and Philosophy of Science, Stanford, 1962, p. 46