%0 Journal Article %A V. M. Borok %T Equivalent systems of linear partial differential equations with constant coefficients %J Doklady Akademii Nauk %D 1957 %P 555-558 %V 117 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1957_117_4_a1/ %G ru %F DAN_1957_117_4_a1