@article{DAN_1980_253_4_a7,
     author = {R. I. Kozlov and V. M. Matrosov},
     title = {The comparison principle in the theory of differential equations with perturbations},
     journal = {Doklady Akademii Nauk},
     pages = {807--811},
     publisher = {mathdoc},
     volume = {253},
     number = {4},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_253_4_a7/}
}