@article{DAN_1961_139_1_a13,
     author = {V. A. Yakubovich},
     title = {The structure of the functional space of complex canonical equations with periodic coefficients},
     journal = {Doklady Akademii Nauk},
     pages = {54--57},
     publisher = {mathdoc},
     volume = {139},
     number = {1},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_139_1_a13/}
}