@article{ZNSL_1997_237_a12,
     author = {S. I. Fedorov},
     title = {On the angles between subspaces, {Muckenhoupt} condition,},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {161--193},
     year = {1997},
     volume = {237},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1997_237_a12/}
}