Gubreev, G. M., and A. A. Tarasenko. “Unconditional Basis Property for Some Families of Functions and Continuous Invertibility of Toeplitz Operators With Unimodular Symbols”. Methods of Functional Analysis and Topology 8, no. 1 (March 25, 2002): 30–35. Accessed December 18, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/174.