@article{MMO_1955_4_a2,
     author = {V. P. Potapov},
     title = {The multiplicative structure of $J$-contractive matrix functions},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {125--236},
     publisher = {mathdoc},
     volume = {4},
     year = {1955},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_1955_4_a2/}
}