@article{DE_1982_18_5_a17,
     author = {G. M. Arhutik},
     title = {Some classes of completely integrable systems of second-order partial differential equations with fixed critical points},
     journal = {Differencialʹnye uravneni\^a},
     pages = {859--867},
     publisher = {mathdoc},
     volume = {18},
     number = {5},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1982_18_5_a17/}
}