Translated from the Russian.

Includes bibliographies.

Characterization of the class of trees /; Directed cycles of any length in digraphs with large semidegrees /; On the minimum of the Hadwiger number for graphs with a given mean degree of vertices /; An upper bound on the number of edges of a hypergraph with a given diameter /; On a theorem from the metric theory of continued fractions /; Surfaces with _g=3 and ^2=3 Part I /; Surfaces with _g=3 and ^2=3 Part II /; A formula for the characters of irreducible finite-dimensional representations of Lie superalgebras of series /; Free groups, the property, and I_1 factors with different countable fundamental groups /; On the conjugacy of finite sets of subgroups in a free product of groups /; On normalizers of Artin groups /; Groups of class and exponent with commutator subgroup of order ^2 /; Subgroups of the full linear group over a ring which contain a group of block triangular matrices / I. G. Dmitriev; S. Kh. Darbinyan; A. V. Kostochka; O. G. Rudenskaya; T. M. Zuparov; Valentin V. Iliev; Valentin V. Iliev; D. A. Leites; V. Ya. Golodets and N. I. Nessonov; I. S. Bezverkhnyaya; V. A. Grinblat; A. L. Vishnevetskii; N. A. Vavilov