@article{SJVM_2017_20_3_a2,
     author = {A. N. Kremlev},
     title = {The plane wave refraction on convex and concave obtuse angles in geometric acoustics approximation},
     journal = {Sibirskij \v{z}urnal vy\v{c}islitelʹnoj matematiki},
     pages = {251--271},
     publisher = {mathdoc},
     volume = {20},
     number = {3},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SJVM_2017_20_3_a2/}
}