Mikhailets, V. A., and A. A. Murach. “Improved Scales of Spaces and Elliptic Boundary-Value Problems. II”.
Ukrains’kyi Matematychnyi Zhurnal 58, no. 3 (March 25, 2006): 352–370. Accessed April 27, 2025.
https://umj.imath.kiev.ua/index.php/umj/article/view/3459.