%0 Journal Article %A A. V. Aminova %A N. A.-M. Aminov %T Fourth-order differential systems with a four-dimensional solvable symmetry group that does not contain the abelian subgroup $G_3$ %J Izvestiâ vysših učebnyh zavedenij. Matematika %D 2005 %P 12-27 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/IVM_2005_6_a1/ %G ru %F IVM_2005_6_a1