The Riemann problem and expansion of entire functions of two variables with respect to quasiexponential bases

It is shown with the aid of the two-dimensional Borel transform that the expansion of entire functions of two variables of a finite degree with respect to a system of primitive functions or with respect to the system of Ozhegov polynomials is possible only when a certain two-dimensional Riemann problem which is equivalent to the Wiener-Hopf problem for a bidomain of the form $\{|z|>r,\ |\zeta|>\rho\}$ is solvable