Karaev, M. T. “Invariant Subspaces, Cyclic Vectors, Commutant and Extended Eigenvectors of Some Convolution Operators”. Methods of Functional Analysis and Topology 11, no. 1 (March 25, 2005): 48–59. Accessed December 16, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/265.