%0 Journal Article %A E. A. Ermolaev %T Extension of classes of exactly solvable degenerate systems of Fedorov equations by means of dual $n$-numbers %J Differencialʹnye uravneniâ %D 1999 %P 1426-1428 %V 35 %N 10 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1999_35_10_a16/ %G ru %F DE_1999_35_10_a16