@article{SJIM_1999_2_1_a14,
     author = {A. I. Rylov},
     title = {The structure of level lines and a~criterion for the similarity of asymptotics in two-dimensional gas flows},
     journal = {Sibirskij \v{z}urnal industrialʹnoj matematiki},
     pages = {139--150},
     publisher = {mathdoc},
     volume = {2},
     number = {1},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SJIM_1999_2_1_a14/}
}