Algebra, topology, differential equations and their applications collected papers dedicated to the 90th birthday of academician Lev Semenovich Pontryagin - Miščenko, Evgenij F. 1922-2010; Anosov, Dmitrij V. 1936-2014; Aseev, Sergei M. (Matematičeskij Institut Imeni V. A. Steklova <Moskva>: Proceedings of the Steklov Institute of Mathematics, 1999)