AnopA. V., KasirenkoT. M., and MurachA. A. 2018. “Irregular Elliptic Boundary-Value Problems and Hörmander Spaces”. Ukrains’kyi Matematychnyi Zhurnal 70 (3), 299-317. https://umj.imath.kiev.ua/index.php/umj/article/view/1558.