Modern Analysis and Applications The Mark Krein Centenary Conference Volume 2: Differential Operators and Mechanics - Adamyan, Vadim M.; Gohberg, Israel; Kochubei, Anatoly; Popov, Gennadiy; Berezansky, Yurij; Gorbachuk, Myroslav; Gorbachuk, Valentyna; Langer, Heinz (Birkhäuser Basel, 2009)