1. V. G. Belikov and E. V. Kompantsev, Farmatsiya, No. 3, 54–58 (1983).
2. L. Mandel'korna [editor], Nonstoichiometric Compounds [in Russian], Moscow (1971), pp. 546–554.
3. Patent 175587, 1981 (Hungary); Ref. Zh. Biokhim., No. 3X217 (1983).
4. Patent Cl-1233, 1981 (Hungary); Ref. Zh. Biokhim., No. 9X127 (1983).
5. Patent 176502, 1982 (Hungary); Ref. Zh. Khimi., No. 4085 (1983).