@article{MZM_2012_92_2_a9,
     author = {P. S. Sarkisyan},
     title = {Canonical {Systems}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {291--301},
     publisher = {mathdoc},
     volume = {92},
     number = {2},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2012_92_2_a9/}
}