Tassawee Thitipak และ Yotsanan Meemark. (2007) An equivalence relation on a set of words of finite length. Chulalongkorn University:ม.ป.ท.Tassawee Thitipak และ Yotsanan Meemark. 2007. An equivalence relation on a set of words of finite length. ม.ป.ท.:Chulalongkorn University;Tassawee Thitipak และ Yotsanan Meemark. An equivalence relation on a set of words of finite length. ม.ป.ท.:Chulalongkorn University, 2007. Print.