Nguyen และ Van Ut. (1997) Knowledge, attitude and behavior of adolescents in Phutthamonthon district, Nakhonphathom province, Thailand towards smoking. Mahidol University,:ม.ป.ท.Nguyen และ Van Ut. 1997. Knowledge, attitude and behavior of adolescents in Phutthamonthon district, Nakhonphathom province, Thailand towards smoking. ม.ป.ท.:Mahidol University,;Nguyen และ Van Ut. Knowledge, attitude and behavior of adolescents in Phutthamonthon district, Nakhonphathom province, Thailand towards smoking. ม.ป.ท.:Mahidol University, 1997. Print.