1. E. S. Dzekker, “A generalization of the equation describing the motion of underground water with a free boundary”,Dokl. Akad. Nauk SSSR [Soviet. Math. Dokl.],202 No. 5, 1031–1033 (1972).
2. V. Z. Furaev, “On global solvability of the first boundary value problem for the generalized Boussinesque equation”,Differentsial’nye Uravneiya [Differential Equations],19, No. 11, 2014–2015 (1983).
3. A. L. Gladkov, “The Cauchy problem in the class of increasing functions for several nonlinear pseudoparabolic equations”,Differentsial’nye Uravneniya [Differential Equations],24, No. 2, 277–288 (1988).
4. A. I. Kozhanov, “Positiveness of solutions to nonlinear pseudoparabolic equations”, in:Partial Differential Equations [in Russian], Proc. Inst. Math. Siberia Division of the Russian Academy of Sciences, Novosibirsk, (1989), pp. 79–92.
5. A. I. Kozhanov,Existence Theorems and Solvability of Boundary Value Problems for Several Classes of Evolution Equations of pseudoparabolic and pseudohyperbolic type [in Russian], Preprint No. 17, Institute of Mathematics, Siberia Division of the Russian Academy of Sciences, Novosibirsk (1990).