Jirada Ueasiriwatthanachai และ Kasma Suwanarak. (2013) Environmental influences on competence in English as a foreign language : A study of Thai undergraduates at an international university in Thailand. National Institute of Development Administration:ม.ป.ท.Jirada Ueasiriwatthanachai และ Kasma Suwanarak. 2013. Environmental influences on competence in English as a foreign language : A study of Thai undergraduates at an international university in Thailand. ม.ป.ท.:National Institute of Development Administration;Jirada Ueasiriwatthanachai และ Kasma Suwanarak. Environmental influences on competence in English as a foreign language : A study of Thai undergraduates at an international university in Thailand. ม.ป.ท.:National Institute of Development Administration, 2013. Print.