1. G. Z. Gershuni and E. M. Zhukhovitskii, ?Convective instability of two immiscible fluids in a spherical cavity,? Uch. Zap. Perm. Un-ta, No. 184 (1968).
2. L. G. Poddubnaya, Yu. P. Rudakov, and G. F. Shaidurov, ?Thermal instability of a two-layer fluid in a spherical cavity,? Uch. Zap. Perm. Un-ta, No. 184 (1968).
3. M. I. Shliomis and V. I. Yakushin, ?Convective instability of two immiscible fluids in a spherical cavity in arbitrary proportions,? Uch. Zap. Perm. Un-ta, No. 216 (1970).
4. R. W. Zeren and W. C. Reynolds, ?Thermal instabilities in two-fluid horizontal layers,? J. Fluid Mech.,53, No. 2 (1972).
5. É. I. Berezovskii, T. L. Perel'man, and E. A. Romashko, ?Convective stability in a system of two unbounded horizontal layers of immiscible fluid,? Inzh.-Fiz. Zh.,27, No. 6 (1974).