@article{SM_1984_48_1_a4,
     author = {V. V. Kucherenko and Yu. V. Osipov},
     title = {The {Cauchy} problem for nonstrictly hyperbolic equations},
     journal = {Sbornik. Mathematics},
     pages = {81--109},
     publisher = {mathdoc},
     volume = {48},
     number = {1},
     year = {1984},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1984_48_1_a4/}
}