Tanisaya Jiriyasin. 2011. The effects of problem-based learning approach on the English oral language performance and discussion skills of Thai undergraduate students. Bangkok:School of Humanities University of the Thai Chamber of Commerce;

Tanisaya Jiriyasin. The effects of problem-based learning approach on the English oral language performance and discussion skills of Thai undergraduate students. Bangkok:School of Humanities University of the Thai Chamber of Commerce, 2011.

Tanisaya Jiriyasin. (2011) The effects of problem-based learning approach on the English oral language performance and discussion skills of Thai undergraduate students (รายงานผลงานวิจัย). School of Humanities University of the Thai Chamber of Commerce:Bangkok.