%0 Journal Article %A A. N. Vasil'ev %A A. S. Stepanenko %T A method of calculating the critical dimensions of composite operators in the massless nonlinear $\sigma$ model %J Teoretičeskaâ i matematičeskaâ fizika %D 1993 %P 160-175 %V 95 %N 1 %U http://geodesic.mathdoc.fr/item/TMF_1993_95_1_a14/ %G ru %F TMF_1993_95_1_a14