1. D. N. Poluboyarinov et al., Izv. Akad. Nauk SSSR, Neorgan. Mat., No. 2 (1966).
2. J. E. Dorn, in: Creep and Recovery [Russian translation], Metallurgizdat, Moscow (1961).
3. L. E. Adushkin et al., Izv. Akad. Nauk SSSR, Neorgan. Mat., No. 4 (1970).