1. V.N. Vigdorovich, A.E. Volpyan, G.M. Kurdyumov, Directed crystallization and physicochemical analysis, Khimia, Moscow, 1976, p. 89 (in Russian).
2. Yu.M. Tairov, V.F. Tsvetkov, Technology of semi-conducting and dielectric materials, Vyschaya Shkola, Moscow, 1983, p. 195 (in Russian).
3. Van den Boomgaard, Philips Res. Rep. 10 (5) (1955) 319.
4. Zur Theorie des Zonenziehens von Halbleitern bei Gegenwart einer Gasphase