%0 Journal Article %A B. F. Skubenko %T An isolation theorem for decomposable forms of purely real algebraic fields of degree $n\ge3$ %J Zapiski Nauchnykh Seminarov POMI %D 1981 %P 167-171 %V 112 %I mathdoc %U http://geodesic.mathdoc.fr/item/ZNSL_1981_112_a12/ %G ru %F ZNSL_1981_112_a12