@article{IM2_1992_39_2_a1,
     author = {O. I. Bogoyavlenskii},
     title = {Breaking solitons. {VI.~Extension} of systems of hydrodynamic type},
     journal = {Izvestiya. Mathematics },
     pages = {959--973},
     publisher = {mathdoc},
     volume = {39},
     number = {2},
     year = {1992},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1992_39_2_a1/}
}