PACS:07.10.−h, 07.50.Ek (all) DOI:10.1070/PU1973v016n01ABEH005156 URL: https://ufn.ru/en/articles/1973/1/m/ Citation: Penner D I, Duboshinskii D B, Kozakov M I, Vermel’ A S, Galkin Yu V "Asynchronous excitation of undamped oscillations" Sov. Phys. Usp.16 158–160 (1973)