%0 Journal Article %A A. K. Rybnikov %T Theory of connections, Cole--Hopf transformations and potentials of second-order partial differential equations %J Izvestiâ vysših učebnyh zavedenij. Matematika %D 2007 %P 50-70 %N 9 %I mathdoc %U http://geodesic.mathdoc.fr/item/IVM_2007_9_a2/ %G ru %F IVM_2007_9_a2