1. ?oban, M.M.: Many-valued mappings and Borel sets, I. Trans. Mosc. Math. Soc.22 (1970) (Transl. Am. Math. Soc. 258?280)
2. ?oban, M.M.: Many-valued mappings and Borel sets, II. Trans. Mosc. Math. Soc.23 (1970) (Transl. Am. Math. Soc. 286?310)
3. Mathematical Surveys;J. Diestel,1977
4. Engelking, R.: Selectors of the first Baire class for semicontinuous set-valued functions. Bull. Acad. Pol. Sci. Ser. Sci. Math.16, 277?282 (1968)
5. Fremlin, D.H.: Measure-additive coverings and measurable selectors. Diss. Math. (to appear)