[1]
Godіch V. I., “On invariant subspaces of completely continuous bisymmetrical operators ”, Ukr. Mat. Zhurn., vol. 18, no. 3, pp. 103–107, Apr. 1966, Accessed: Apr. 13, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/8742