@article{RM_1989_44_4_a6,
     author = {T. D. Dzhuraev and Ya. Popelek},
     title = {On~the canonical forms of third-order partial differential equations},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {203--204},
     publisher = {mathdoc},
     volume = {44},
     number = {4},
     year = {1989},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1989_44_4_a6/}
}