@article{MZM_1990_47_3_a20,
     author = {V. E. Shemarulin},
     title = {Higher symmetries and laws of conservation of an equation of one-dimensional planar isentropic flows of a~polytropic gas},
     journal = {Matemati\v{c}eskie zametki},
     pages = {138--140},
     publisher = {mathdoc},
     volume = {47},
     number = {3},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1990_47_3_a20/}
}