@article{DE_1996_32_11_a12,
     author = {N. N. Nefedov},
     title = {The method of differential inequalities for nonlinear singularly perturbed problems with contrast structures of step type in the critical case},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1529--1537},
     publisher = {mathdoc},
     volume = {32},
     number = {11},
     year = {1996},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1996_32_11_a12/}
}