(NdRAGOCENNYE I CWETNYE KAMNI KAK POLEZNOE ISKOPAEMOE (B/s - (NsMIRNOW(B, (Nw(B.(Ni(B.s ((NmOSKWA (B:s (NnAUKA(B,s, 1973)
Keywords: (NdRAGOCENNYE KAMNIs; (NcWETNYE KAMNIs