@article{10_21136_CMJ_1995_128543,
     author = {Kozera, Ryszard},
     title = {Reducing real almost-linear second-order partial differential operators in two independent variables to a canonical form},
     journal = {Czechoslovak Mathematical Journal},
     pages = {481--490},
     publisher = {mathdoc},
     volume = {45},
     number = {3},
     year = {1995},
     doi = {10.21136/CMJ.1995.128543},
     mrnumber = {1344514},
     zbl = {0838.35030},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1995.128543/}
}