@article{DAN_1957_117_3_a5,
     author = {L. S. Rakovshchik},
     title = {On a condition for unlimited applicability of {Chaplyguin's} theorem on inequalities to systems of first order differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {378--379},
     publisher = {mathdoc},
     volume = {117},
     number = {3},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_117_3_a5/}
}