[1] O. DEMUTH: The Lebesgue measurability of sets in constructive mathematics. Comment. Math. Univ. Carolinae 10 (1969), 463-492 (in Russian). MR 0259055

[2] O. DEMUTH A. KUČERA: Remarks on constructive mathematical analysis. Logic Colloquium '78 (Boffa, van Dalen, McAlcon editors), North-Holland, Amsterdam, 1979, 81-129. MR 0567667

[3] R. M. FRIEDBERG: A criterion for completeness of degrees of unsolvability. J. Symbol. Logic 22 (1957), 159-160. MR 0098025 | Zbl 0078.00602

[4] C. G. JOCKUSCH: Degrees in which the recursive sets are uniformly recursive. Canad. J. Math. 24 (1972), 1092-1099. MR 0321716 | Zbl 0221.02029

[5] C. G. JOCKUSCH R. I. SCARE: $\Pi_1^0$ classes and degrees of theories. Trans. Amer. Math. Soc. 173 (1972), 33-56. MR 0316227

[6] D. A. MARTIN: Classes of recursively enumerable sets and degrees of unsolvability. Z. Math. Logik Grundlagen Math. 12 (1966), 295-310. MR 0224469

[7] H. ROGERS: Theory of recursive functions and effective computability. McGraw-Hill, New York, 1967. MR 0224462 | Zbl 0183.01401

[8] I. D. ZASLAVSKIJ G. S. CEJTIN: On singular coverings and related properties of constructive functions. Trudy Mat. Inst. Steklov. 67 (1962), 458-502; English transl. Amer. rath. Soc. Transl. (2) 98 (1971), 41-89. MR 0152428