@article{DE_2001_37_9_a4,
     author = {A. M. Samoilenko and A. A. Boichuk and L. I. Karandzhulov},
     title = {Fredholm {Boundary} {Value} {Problems} with a {Singular} {Perturbation}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1186--1193},
     publisher = {mathdoc},
     volume = {37},
     number = {9},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2001_37_9_a4/}
}