Raweewon Sananworakiat. (2000) A proposed model of provincial environmental education centers. Mahidol University,:ม.ป.ท.Raweewon Sananworakiat. 2000. A proposed model of provincial environmental education centers. ม.ป.ท.:Mahidol University,;Raweewon Sananworakiat. A proposed model of provincial environmental education centers. ม.ป.ท.:Mahidol University, 2000. Print.