On undecidable sentences in formalized mathematical systems / Andrzej Mostowski -- On the consistency of some propositions of the descriptive theory of sets / P.S. Novikov -- Some generalizations of the concept of a normal algorithm / N.M. Nagornyĭ -- On a minimal alphabet of algorithms over a given alphabet / N.M. Nagornyĭ -- On constructive functions / A.A. Markov -- Solution of Post's reduction problem and some other problems of the theory of algorithms, I / A.A. Mučnik --On the definition of an algorithm / A.N. Kolmogorov and V.A. Uspenskiĭ -- Solution of a problem of Halmos (concept of a recurrent numerical sequence) / F.V. Širokov -- The equations and convergence of a differential-difference method (the method of lines) / V.I. Lebedev -- On the converses of Ljapunov's theorem on stability and Persidiskiĭ's theorem on uniform stability / Jaroslav Kurzweĭl and Ivo Vrkoč -- On the number of limit cycles of the equation dy/dx = cx+dy+P(x, y)/ax+by+Q(x, y), where P(x, y) and Q(x, y) are homogeneous polynomials of degree n / B.M. Peretjagin -- Some problems in the theory of quasilinear equations / I.M. Gelʹfand