%0 Journal Article %A D. V. Ktitarev %T Feynman's formula in a phase space for a certain class of systems of pseudodifferential equations %J Matematičeskie zametki %D 1987 %P 40-49 %V 42 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZM_1987_42_1_a4/ %G ru %F MZM_1987_42_1_a4