Songgot Paanchiangwong. (1999) A study of interference of northeastern Thai dialect in standard Thai : case of Muang district Ubonratchathani province. Mahidol University,:ม.ป.ท.Songgot Paanchiangwong. 1999. A study of interference of northeastern Thai dialect in standard Thai : case of Muang district Ubonratchathani province. ม.ป.ท.:Mahidol University,;Songgot Paanchiangwong. A study of interference of northeastern Thai dialect in standard Thai : case of Muang district Ubonratchathani province. ม.ป.ท.:Mahidol University, 1999. Print.