1. V. M. Entov and A. M. Polishchuk, ?On the part played by sorption processes in the motion of polymer solutions in a porous medium,? Izv. Akad. Nauk SSSR, Mekh. Zhidk. Gaza, No. 3 (1975).
2. V. M. Entov, A. Ya. Khavkin, and É. Chen-Sin, ?Calculations of the displacement of oil by a solution of an active additive,? in: Numerical Solution to Problems of the Flow of a Multiphase Incompressible Fluid in Porous Media tin Russian], Novosibirsk (1977).
3. A. G. Kulikovsky, ?On the discontinuous solutions in mechanics of continuous media,? Theoretical and Appl. Mechanics, Proc. 14th IUTAM Congress, Delft, 1976, North-Holland, Amsterdam (1977).
4. I. M. Gel'fand, ?Some problems in the theory of quasilinear equations,? Usp. Mat. Nauk,14, No. 2 (1959).
5. O. A. Oleinik, ?Discontinuous solutions of nonlinear differential equations,? Usp. Mat. Nauk, 12, No. 3 (1957).