O. M. Tymokha, V. L. Makarov, I. O. Shevchuk, V. Ya. Gutlyanskii, V. F. Babenko, S. B. Vakarchuk, O. V. Davydov, V. A. Kofanov, N. V. Parfinovych, A. S. Romanyuk, A. S. Serdyuk, I. V. Sokolenko
Institute of Mathematics of the National Academy of Sciences of Ukraine, Kyiv
