(NaSIMPTOTI^ESKIE METODY W TEORII LINEJNYH DIFFERENCIALXNYH URAWNENIJs - (NfE]ENKO(B,(Ns(B. (Nf(B.s (NsTEPAN fEDOROWI^s; (N{KILX(B,(Nn(B. (Ni(B.s (NnIKOLAJ iWANOWI^s; (NnIKOLENKO(B,(Nl(B. (Nd(B.s (NlARISA dANILOWNAs ((Nk(B.s (NnAUKOWA DUMKAs, 1966)