@article{DAN_1983_269_6_a3,
     author = {N. I. Vulpe},
     title = {Construction of a minimal complete system of orthogonal invariants for a two-dimensional system of differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {1299--1302},
     publisher = {mathdoc},
     volume = {269},
     number = {6},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_269_6_a3/}
}