@article{DE_1985_21_10_a18,
     author = {A. M. Il'in},
     title = {Investigation of singularly perturbed boundary value problems by the method of matching asymptotic expansions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1760--1766},
     publisher = {mathdoc},
     volume = {21},
     number = {10},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1985_21_10_a18/}
}