1. I. Bucur and A. Deleanu, Introduction to the Theory of Categories and Functors, Wiley-Interscience, New York (1968).
2. S. S. Goncharov, "Self-stability and computable Families of constructivizations," Algebra Logika,14, No. 6, 647–680 (1975).
3. S. S. Goncharov, "On the number of non-self-equivalent constructivizations," Algebra Logika,16, No. 3, 257–263 (1977).
4. S. S. Goncharov, "Non-self-equivalent constructivizations of Boolean algebras," Mat. Zametki,19, No. 6, 853–858 (1976).
5. V. P. Dobritsa, "On recursively enumerable classes of constructive extensions and self-stability of algebras," Sib. Mat. Zh.,16, No. 6, 1148–1156 (1975).