“…The Riemann -Hilbert problem for a holomorphic vector in multidimensional domain is reduced to the integral Fredholm equation. In the papers [15,16], the index is calculated and condition for the Noether property of a singular integral equation with a continuous kernel is established. Eigenvalue problems of the Cauchy-Riemann differential operator with regular boundary value conditions, in particular with nonlocal boundary value conditions [11], as well as with Dirichlet type homogeneous boundary value conditions [17,18], where the initial operator is proved to be Volterre, are reduced to the similar problem.…”