@article{DAN_1989_309_3_a1,
     author = {Yu. V. Gavrilenko},
     title = {Principal solutions and automorphism groups of systems of},
     journal = {Doklady Akademii Nauk},
     pages = {524--528},
     publisher = {mathdoc},
     volume = {309},
     number = {3},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_309_3_a1/}
}