@article{DAN_1976_231_5_a1,
     author = {Yu. Ya. Belov},
     title = {On some systems of linear differential equations with a small parameter},
     journal = {Doklady Akademii Nauk},
     pages = {1037--1040},
     publisher = {mathdoc},
     volume = {231},
     number = {5},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1976_231_5_a1/}
}