1. Ambos-Spies, On the structure of the recursively enumerable degrees, Ph. D. thesis, University of Munich, 1980.
2. Ambos-Spies, C. Jockusch, R. Shore and R. Soare, An algebraic decomposition of the recursively enumerable degrees and classes equal to the promptly simple degrees (to appear).
3. Two recursively enumerable sets of incomparable degrees of unsolvability (solution of Post’s problem, 1944);Friedberg, Richard M.;Proc. Nat. Acad. Sci. U.S.A.,1957
4. Lower bounds for pairs of recursively enumerable degrees;Lachlan, A. H.;Proc. London Math. Soc. (3),1966
5. Recursively enumerable generic sets;Maass, Wolfgang;J. Symbolic Logic,1982