@article{DE_1976_12_10_a6, author = {V. F. Butuzov}, title = {A singularly perturbed equation of elliptic type with two small parameters}, journal = {Differencialʹnye uravneni\^a}, pages = {1793--1803}, publisher = {mathdoc}, volume = {12}, number = {10}, year = {1976}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1976_12_10_a6/} }