Golubov B. I. Иванович RussiaMoscow Lomonosov Moscow State University, Institute of Mechanics, Russia, 119192, Moscow, Michurinskii pr., 1 golubov@mail.mipt.ru Author's articles 18th International Saratov Winter School “Contemporary Problems of Function Theory and Their Applications” 19th International Saratov Winter School “Contemporary Problems of Function Theory and Their Applications“