Urairat Thongpinit. 1996. Motivation and achievement in learning English resulting from development and implementation of lessons based on the natural approach. Graduate School, Chiang Mai University;

Urairat Thongpinit. Motivation and achievement in learning English resulting from development and implementation of lessons based on the natural approach. . Chiang Mai:Chiang Mai University, 1996.

Urairat Thongpinit. (1996) Motivation and achievement in learning English resulting from development and implementation of lessons based on the natural approach . Chiang Mai University/Chiang Mai.