%0 Journal Article %A B. O. Makarevich %T Open symmetric orbits of reductive groups in symmetric $R$-spaces %J Sbornik. Mathematics %D 1973 %P 406-418 %V 20 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1973_20_3_a5/ %G en %F SM_1973_20_3_a5