Ladapan Saengklai และ Somsook Khongpun. (2008) Assessment of drinking water for school students after intervention by providing knowledge of sanitary conditions. Thammasat University:ม.ป.ท.Ladapan Saengklai และ Somsook Khongpun. 2008. Assessment of drinking water for school students after intervention by providing knowledge of sanitary conditions. ม.ป.ท.:Thammasat University;Ladapan Saengklai และ Somsook Khongpun. Assessment of drinking water for school students after intervention by providing knowledge of sanitary conditions. ม.ป.ท.:Thammasat University, 2008. Print.