1. Korolev Yu. M., Stolyarov V. I.,Restoration of fluorides of refractory metals hydrogen(Metallurgy, Moscow, 1981)
2. Golovanov U. N., Kadimet S. N.., Krasovskii A. I. etc. The electronic technics. Technology, production process and equipment43(1971)
3. Neiberlein V. A., Amer. J. Ceramic. Soc. Bulletin48(1965)
4. Averin I. B., Plotnikov U. P., Mech. Eng.107(1979)