%0 Journal Article %A O. M. Dzhokhadze %T Laplace Invariants for Some Classes of Linear Partial Differential Equations %J Differencialʹnye uravneniâ %D 2004 %P 58-68 %V 40 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_2004_40_1_a7/ %G ru %F DE_2004_40_1_a7