@article{DE_1979_15_10_a12,
     author = {V. F. Butuzov},
     title = {An angular boundary layer in singularly perturbed problems with partial derivatives},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1848--1862},
     publisher = {mathdoc},
     volume = {15},
     number = {10},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1979_15_10_a12/}
}