%0 Journal Article %A M. L. Nekrasov %A V. E. Rochev %T The $\rm O^-$ nonet and~solution of the~$U(1)$ problem in~a~nonperturbative approximation of~quantum chromodynamics %J Teoretičeskaâ i matematičeskaâ fizika %D 1988 %P 171-179 %V 74 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_1988_74_2_a1/ %G ru %F TMF_1988_74_2_a1