1. L. D. Landau and E. M. Lifshits, Theoretical Physics [in Russian], Vol. 6, Nauka, Moscow (1986).
2. I. V. Denisova and V. A. Solonnikov, “Solvability in Hölder spaces for a model initial boundary-value problem generated by a problem on the motion of two fluids,” J. Math. Sci, 70, 1717–1746 (1994).
3. I. V. Denisova, “Solvability in Hölder spaces of a linear problem concerning the motion of two fluids separated by a closed surface,” St.Petersburg Math. J., 5, No. 4, 765–787 (1994).
4. I. V. Denisova and V. A. Solonnikov, “Classical solvability of the problem on the motion of two viscous incompressible fluids,” St. Petersburg Math. J., 7, No. 5, 75–786 (1996).
5. I. V. Denisova, “Model problem connected with the motion of two incompressible fluids,” Adv. Math. Sci. Appl., 17, No. 1, 195–223 (2007).