(NdINAMI^ESKAQ TEORIQ MAGNITNOGO RASSEQNIQ LU^EJ W ANTIFERROMAGNETIKAH (B/s - (NbABU[KIN(B, (Nf(B.(Na(B.s ((NlENINGRAD (B:s (NiZD(B-(NWO lENINGR(B. (NUN(B-(NTA(B,s, 1979)