@article{TMF_1995_105_2_a1,
     author = {S. R. Svirshchevskii},
     title = {Nonlinear differential operators of the first and the second orders, possessing invariant linear spaces of the maximal dimension},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {198--207},
     publisher = {mathdoc},
     volume = {105},
     number = {2},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1995_105_2_a1/}
}