1. I. E. Bekker, Zavod. Lab., No. 1 (1948).
2. G. I. Sayutin, Fiz. Khim. Mekhan. Met.,7, No. 5 (1971).
3. S. Z. Bokshtein, in: Surface Diffusion and Flow [in Russian], Nauka, Moscow (1969).
4. Yu. M. Vinogradov, in: Increasing the Life of Machine Parts [in Russian], Mashgiz, Moscow (1959).