1. V. Becker-Barbrock, Industrie Anzeiger (1965) 671–677.
2. F.V. Sedykin, in: Sinteticheskie Almazy v Promyshlennosti, Naukova Dumka, Kijev, 1974, pp. 209–212 (in Russian).
3. G.S. Kreymer, Prochnost Tverdykh Splavov, Metallurgiya, Moscow, 1971, p. 247 (in Russian).