Sasikarn Sasitornwetchakun และ Tipamas Chumworatayee. (2008) Roles of background knowledge and L2 proficiency in L2 reading. Language Institute, Thammasat University,:ม.ป.ท.Sasikarn Sasitornwetchakun และ Tipamas Chumworatayee. 2008. Roles of background knowledge and L2 proficiency in L2 reading. ม.ป.ท.:Language Institute, Thammasat University,;Sasikarn Sasitornwetchakun และ Tipamas Chumworatayee. Roles of background knowledge and L2 proficiency in L2 reading. ม.ป.ท.:Language Institute, Thammasat University, 2008. Print.