Tài liệu tham khảo WikiPedia: Pa_Khóa //tools.wmflabs.org/geohack/geohack.php?language=v... http://www.gso.gov.vn/phuong-phap-thong-ke/danh-mu... https://thuvienphapluat.vn/van-ban/Bo-may-hanh-chi...
