A cornucopia of minimal degrees
Leonard P. Sasso · Journal of Symbolic Logic · 1970
The first minimal degree construction is due to Spector [7]. To this Sacks [5] has added the priority method of Friedberg [1] and Muchnik [4] to obtain a minimal degree less than 0′. Sacks' methods have been modified in several directions to obtain minimal degrees satisfying various incomparability conditions.