1. J. Shyne, V. Zackay, and D. Schmatz, TASM, Vol. 52 (1960).
2. Ya. M. Potak et al., MiTOM, No. 5 (1961).
3. M. L. Bernshtein, É. L. Demina, K. É. Safonova, MiTOM, No. 1 (1962).
4. L. I. Kogan and R. I. Éntin, MiTOM, No. 1 (1962).
5. D. Schmatz and V. Zackay, TASM, Vol. 51 (1959).