%0 Journal Article %A S. P. Tsarev %T Factoring linear partial differential operators and the Darboux method for integrating nonlinear partial differential equations %J Teoretičeskaâ i matematičeskaâ fizika %D 2000 %P 144-160 %V 122 %N 1 %U http://geodesic.mathdoc.fr/item/TMF_2000_122_1_a11/ %G ru %F TMF_2000_122_1_a11