On the existence of configurations of subspaces in a Hilbert space with fixed angles. Popova, Natasha D.; Samoĭlenko, Yurii S. — 2006 SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
On transitive systems of subspaces in a Hilbert space. Moskaleva, Yuliya P.; Samoĭlenko, Yurii S. — 2006 SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]