@article{IVM_1970_6_a3,
     author = {S. J. Bilchev},
     title = {Systems of two first order partial differential equations (the conservation laws)},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {28--34},
     publisher = {mathdoc},
     number = {6},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1970_6_a3/}
}