PACS:01.60.+q DOI:10.1070/PU1969v011n05ABEH003751 URL: https://ufn.ru/en/articles/1969/5/p/ Citation: Berg A I, Vvedenskii B A, Zernov D, Kobzarev Yu B, Pistol’kors A A "Vladimir Aleksandrovich Kotel'nikov (in honor of his sixtieth birthday)" Sov. Phys. Usp.11 778–779 (1969)