%0 Journal Article %A A. M. Vershik %T Many-valued measure-preserving mappings (polymorphisms) and Markovian operators %J Zapiski Nauchnykh Seminarov POMI %D 1977 %P 26-61 %V 72 %I mathdoc %U http://geodesic.mathdoc.fr/item/ZNSL_1977_72_a1/ %G ru %F ZNSL_1977_72_a1