[1]
V. S. Il’kiv, N. I. Strap, and I. I. Volyanska, “Solvability conditions of a nonlocal boundary value problem for a differential-operator equation with nonlinearity in a refined Sobolev scale of spaces of functions of several real variables”, Ukr. Mat. Zhurn., vol. 72, no. 4, pp. 452-466, Mar. 2020.