Volkova, M. G., and G. M. Gubreev. “Unconditional Bases of De Branges Spaces and Interpolation Problems Corresponding to Them”. Methods of Functional Analysis and Topology 17, no. 2 (June 25, 2011): 144–149. Accessed December 15, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/478.