Mozel’, V. A., and V. A. Chernetskii. 2001. “Algebra of Bergman Operators With Automorphic Coefficients and Parabolic Group of Shifts”. Ukrains’kyi Matematychnyi Zhurnal 53 (9): 1218-23. https://umj.imath.kiev.ua/index.php/umj/article/view/4340.