1. J. Langmuir, Phys. Rev., No. 2, 329 (1913).
2. E. I. Shetnikov and D. P. Shveikii, Poroshkovaya Met., No. 4 (1965).
3. G. A. Semenov, The Mass Spectrometer for Investigating the Processes of Vaporization at High Temperature [in Russian], GosNITI, No. 8 (1965).
4. D. N. Poluboyarinov and E. S. Lukin, Super-Refractory Materials [in Russian], Izd-vo Metailurgiya (1966).
5. V. C. Bakunov et al., Proc. D. I. Mendeleev Moscow Inst. Chem. Tech., No. 5, 216 (1966).