@article{SM_1973_20_1_a2,
     author = {B. V. Verbitskii},
     title = {On~a~global property of a~matrix-valued function of one variable},
     journal = {Sbornik. Mathematics},
     pages = {53--65},
     publisher = {mathdoc},
     volume = {20},
     number = {1},
     year = {1973},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1973_20_1_a2/}
}