%0 Journal Article %A V. G. Kanovei %A M. Reeken %T Some new results on Borel irreducibility of equivalence relations %J Izvestiya. Mathematics %D 2003 %P 55-76 %V 67 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_2003_67_1_a3/ %G en %F IM2_2003_67_1_a3