1. I. R. Downing and L. G. Mellen, Rev. Instrum.,17, No. 6, 218 (1946).
2. V. A. Chernyshev, S. T. Pantyukhov, and V. M. Alekseenko, Tr. Mos. Energ. Inst.456, 66?71 (1980).
3. V. V. Brodskii, Priborostroenie, No. 7, 8?13 (1956).
4. L. P. Khavkin, Prib. Tekh. Eksp., No. 5, 101?106 (1960).
5. V. A. Chernyshev, S. T. Pantyukhov, and A. P. Kharin, Prib. Tekh. Eksp., No. 2, 183?185 (1978).