Panitda Reanjaroensuk. (1999) An investigation into the English vocabulary proficiency in a natural science context of first year arts and science oriented university students. Mahidol University,:ม.ป.ท.Panitda Reanjaroensuk. 1999. An investigation into the English vocabulary proficiency in a natural science context of first year arts and science oriented university students. ม.ป.ท.:Mahidol University,;Panitda Reanjaroensuk. An investigation into the English vocabulary proficiency in a natural science context of first year arts and science oriented university students. ม.ป.ท.:Mahidol University, 1999. Print.