1. S. V. Manakov, Funktsion. Analiz Prilozh. 10(4), 93 (1976).
2. A. P. Veselov, Dokl. Akad. Nauk 270(6), 1298 (1983).
3. O. I. Bogoyavlenskii, Dokl. Akad. Nauk 287(5), 1105 (1986).
4. M. V. Shamolin, Vestn. MSU Ser. Mat. Mekh., No. 1, 52 (1992).
5. M. V. Shamolin, Method of Analysis of Dynamic Sets with Variable Dissipation in Dynamics of Solid (Ekzamen, Moscow, 2007) [in Russian].