Ivasiuk, I. Ya. “Generalized Selfadjoinness of Differentiation Operator on Weight Hilbert Spases”. Methods of Functional Analysis and Topology 13, no. 4 (December 25, 2007): 333–337. Accessed December 16, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/361.