/images/1041385860215607387/1270120559937851534/luan-ve-phuong-phap-cua-do-nam-phu-huu-hieu-nhat-chuong-39-c39-chuong-39.txt?ex=66b28b73&is=66b139f3&hm=3f1ebfd604f05811ea647784af0c609c7e2842fb7a743fab12d54775626a51d4&