Sutthirak Sapsirin. 2006. A study of trait factors of oral language ability in a computer-based speaking test for Thai university students. Field of Study English as an International Language, Chulalongkorn University;
Sutthirak Sapsirin. (2006) A study of trait factors of oral language ability in a computer-based speaking test for Thai university students . Chulalongkorn University/Bangkok.
Sutthirak Sapsirin. A study of trait factors of oral language ability in a computer-based speaking test for Thai university students. . Bangkok:Chulalongkorn University, 2006.
Sutthirak Sapsirin. (2006) A study of trait factors of oral language ability in a computer-based speaking test for Thai university students . Chulalongkorn University/Bangkok.