@article{SM_2006_197_5_a3,
     author = {M. V. Korobkov and E. Yu. Panov},
     title = {Isentropic solutions of quasilinear equations of the first order},
     journal = {Sbornik. Mathematics},
     pages = {727--752},
     publisher = {mathdoc},
     volume = {197},
     number = {5},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2006_197_5_a3/}
}