@article{FPM_1999_5_2_a2,
     author = {V. F. Butuzov and I. V. Nedelko},
     title = {On~periodic contrast structures in singularly perturbed elliptic equations},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {385--409},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_1999_5_2_a2/}
}