
Necessary and sufficient conditions for the possibility of approximating a function on a circumference by rational fractions, expressed in terms directly connected with the distribution of poles of the approximating fractions G. Ts. Tumarkin

969 

Stability of solutions of differentialdifference equations with periodic coefficients Z. I. Rekhlitskii

981 

Certain characteristic properties of differential operators of infinite order Yu. F. Korobeinik

993 

Continuous branches of semieigenvectors of nonlinear operators I. A. Bakhtin

1017 

Boundary value problems for equations of higher orders in infinite regions G. N. Finozhenok

1027 

Reducibility of a system of ordinary differential equations in a neighborhood of a smooth toroidal manifold A. M. Samoilenko

1047 

Rational surfaces with a pencil of elliptic curves I. V. Dolgachev

1073 

Integration of almost periodic functions with values in a Banach space B. M. Levitan

1101 

Structure of unitary representations of locally bicompact groups and symmetric representations of algebras in the Pontrjagin spaces $\Pi_{k}$ M. A. Naimark

1111 

The Cauchy problem for equations of odd order which are correct in the sense of I. G. Petrovskii V. M. Borok, Ya. I. Zhitomirskii

1133 

An integral associated with Riemannian symmetric spaces of nonpositive curvature S. G. Gindikin, F. I. Karpelevich

1147 

A proof of commensurability of the Favard and Hausdorff measures for sets of bounded variations V. A. Zhil'tsov

1157 

Best approximations of classes of periodic functions by trigonometric polynomials A. V. Efimov

1163 

The order and the index of an elliptic curve P. A. Medvedev

1179 

Walsh series and the theorem of Men'sov on “correction” of functions B. D. Kotlyar

1193 