1. The Hopf Bifurcation and its Applications;Marsden,1976
2. On generation of auto-oscillations from the equilibrium;Krasnosel'skii;Automat. Telemech.,1973
3. A method of parameter functionalization in the problem of bifurcation points;Kozjakin;Dokl. Akad. Nauk SSSR,1980
4. Subfurcation of periodic oscillations;Kozjakin;Dokl. Akad. Nauk SSSR,1977