1. R.B. Jensen, The Σn uniformization lemma, unpublished mimeographed notes.
2. Metarecursives sets;Kreisel;J. Symbolic Logic,1965
3. On suborderings of the α-recursively enumerable α-degrees;Lerman;Ann. Math. Logic,1972
4. Contributions to metarecursion theory;MacIntyre;Ph. D. Thesis, M.I.T.,1968
5. J. MacIntyre, Minimal α-recursion theoretic degrees, J. Symbolic Logic, to appear.