Tài liệu tham khảo WikiPedia: Liêm_Túc //tools.wmflabs.org/geohack/geohack.php?language=v... http://www.gso.gov.vn/phuong-phap-thong-ke/danh-mu... http://mic.gov.vn/uploads/20100623/E124-2009%20(31... https://web.archive.org/web/20130324095035/http://...
