T. Zinchenko and A. A. Murach, “Parameter-elliptic operators on the extended Sobolev scale”, MFAT, vol. 19, no. 1, pp. 29–39, Mar. 2013, Accessed: Dec. 16, 2025. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/533