@article{DAN_1958_120_5_a9,
     author = {E. F. Mishchenko and L. S. Pontryagin},
     title = {A proof of some asymptotic formulas for solutions of differential equations involving a small parameter},
     journal = {Doklady Akademii Nauk},
     pages = {967--969},
     publisher = {mathdoc},
     volume = {120},
     number = {5},
     year = {1958},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1958_120_5_a9/}
}