Tài liệu tham khảo WikiPedia: Rattaphum (huyện) http://www.amphoe.com/menu.php?mid=1&am=624&pv=56 //tools.wmflabs.org/geohack/geohack.php?language=v... http://www.ratchakitcha.soc.go.th/DATA/PDF/2482/A/...