@article{AA_2008_20_1_a0,
     author = {V. M. Babich},
     title = {Factorizability of matrix functions: a direct proof},
     journal = {Algebra i analiz},
     pages = {3--33},
     publisher = {mathdoc},
     volume = {20},
     number = {1},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_2008_20_1_a0/}
}