[1]
M. A. Vlasenko and N. D. Popova, “On configurations of subspaces of a Hilbert space with fixed angles between them”, Ukr. Mat. Zhurn., vol. 56, no. 5, pp. 606–615, May 2004, Accessed: Apr. 23, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3781