@article{FPM_1998_4_3_a0,
     author = {A. B. Vasil'eva and V. F. Butuzov and N. N. Nefedov},
     title = {Contrast structures in singularly perturbed problems},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {799--851},
     publisher = {mathdoc},
     volume = {4},
     number = {3},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_1998_4_3_a0/}
}