Baranetskij, Ya.O., I.Ya. Ivasiuk, P.I. Kalenyuk, and A.V. Solomko. 2018. “The Nonlocal Boundary Problem With Perturbations of Antiperiodicity Conditions for the Elliptic Equation With Constant Coefficients”. Carpathian Mathematical Publications 10 (2):215-34. https://doi.org/10.15330/cmp.10.2.215-234.