@article{DE_2006_42_6_a6,
     author = {V. F. Butuzov and E. A. Derkunova},
     title = {On a singularly perturbed system of first-order partial differential equations with various degrees of a small parameter},
     journal = {Differencialʹnye uravneni\^a},
     pages = {775--789},
     year = {2006},
     volume = {42},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2006_42_6_a6/}
}