@article{DE_1973_9_11_a2,
     author = {B. M. Arkhipov and A. Ya. Khokhryakov},
     title = {Strictly positive solutions of periodic systems of ordinary differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1945--1955},
     publisher = {mathdoc},
     volume = {9},
     number = {11},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_11_a2/}
}