%0 Journal Article
%A D. V. Matyukhin
%T On positive-definite biquadratic forms that cannot be represented as the sum of squares of bilinear forms
%J Vestnik Moskovskogo universiteta. Matematika, mehanika
%D 1995
%P 29-33
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/VMUMM_1995_2_a5/
%G ru
%F VMUMM_1995_2_a5