1. P. Olver, Applications of Lie Groups to Differential Equations, Springer-Verlag, New-York (1986).
2. L. V. Ovsyannikov, Group Analysis of Differential Equations [in Russian], Nauka, Moscow (1978).
3. L. V. Ovsyannikov, Lectures on the Foundations of Gas Dynamics [in Russian], Nauka, Moscow (1981).
4. W. I. Fushchych, “Symmetry in the problems of mathematical physics,” in: Algebraic-Theoretical Studies in Mathematical Physics [in Russian], Institute of Mathematics, Ukrainian Academy of Sciences, Kiev (1981), pp. 6–28.
5. A. F. Barannyk and I. I. Yuryk, “On a new method for constructing exact solutions of the nonlinear differential equations of mathematical physics,” J. Phys. A: Math. Gen.,31, No. 21, 4899–4907 (1998).