1. B. G. Boldyrev, Author's Certificate No. 178387; Izobreteniya, No. 3 (1966).
2. B. G. Boldyrev, Ya. I. Stoyanovskaya, and L. A. Vanchak, Zh. Organ. Khim.,3, 1073 (1967).
3. B. G. Boldyrev and Ya. I. Stoyanovskaya, Author's Certificate No. 188962; Izobreteniya, No. 23 (1966).
4. I. V. Aplyak, B. G. Boldyrev, and E. L. Mel'nichenko, Author's Certificate No. 186849; Izobreteniya, No. 19 (1966).