@article{DE_1976_12_5_a19,
     author = {M. M. Smirnov},
     title = {Functionally invariant solutions and the nonuniqueness of the solution of the {Darboux} problem for degenerate hyperbolic equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {937--939},
     publisher = {mathdoc},
     volume = {12},
     number = {5},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_5_a19/}
}