1. A. V. Gurevich and A. B. Shvartsburg, Nonlinear Theory of Radiowave Propagation in Ionosphere (Nauka, Moscow, 1973) [in Russian].
2. A. B. Shvartsburg, Geometric Optics in Nonlinear Wave Theory (Nauka, Moscow, 1977).
3. E. N. Pelinovskii, Hydrodynamics of Tsunami Waves (Inst. Prikl. Fiz. Ross. Akad. Nauk, Nizhnii Novgorod, 1996).
4. E. A. Kuznetsov and V. P. Ruban, “Collapse of vortex lines in hydrodynamics,” Zh. Éksper. Teoret. Fiz. 118 (4), 893–905 (2000).
5. N. M. Zubarev, “Development of the Instability of the Charged Surface of Liquid Helium: Exact solutions,” Pis’ma Zh. Éksper. Teoret. Fiz. 71 (9), 534–538 (2000).