Small denominators. I: Mapping the circle onto itself. (Kleine Nenner. I: Über Abbildungen der Kreisperipherie auf sich.) (Russian) Zbl 0135.42603
Izv. Akad. Nauk SSSR, Ser. Mat. 25, 21-86 (1961); correction ibid. 28, 479-480 (1964).
MSC:
37E10 | Dynamical systems involving maps of the circle |
70-XX | Mechanics of particles and systems |
34-XX | Ordinary differential equations |