%0 Journal Article %A Yu. L. Sachkov %T Complete description of the Maxwell strata in the %J Sbornik. Mathematics %D 2006 %P 901-950 %V 197 %N 6 %U http://geodesic.mathdoc.fr/item/SM_2006_197_6_a5/ %G en %F SM_2006_197_6_a5