Tài liệu tham khảo WikiPedia: Khok Pho (huyện) http://www.amphoe.com/menu.php?mid=1&am=353&pv=30 //tools.wmflabs.org/geohack/geohack.php?language=v... http://www.ratchakitcha.soc.go.th/DATA/PDF/2482/A/...