@article{DAN_1980_253_6_a4,
     author = {A. A. Martynyuk},
     title = {The comparison principle and averaging in systems with fast and slow motions},
     journal = {Doklady Akademii Nauk},
     pages = {1307--1310},
     publisher = {mathdoc},
     volume = {253},
     number = {6},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_253_6_a4/}
}