A. A. Murach and T. Kasirenko, “Elliptic problems with boundary operators of higher orders in Hörmander–Roitberg spaces”, MFAT, vol. 24, no. 2, pp. 120–142, Jun. 2018, Accessed: Dec. 15, 2025. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/690