1. Aspects of Constructibility;Devlin,1973
2. Two r.e. sets of incomparable degrees of unsolvability;Friedberg,1957
3. Recursion on Inadmissible Ordinals;Friedmań,1976
4. S. D. Friedman, β-Recursion Theory, Trans. Amer. Math. Soc., in press.
5. Inadmissible recursion theory;Friedman;Bull. Amer. Math. Soc.,1977