Ploysongsang Panpothong และผู้แต่งคนอื่นๆ. (2006) The understanding and application of the communicative language teaching approach of secondary school teachers in Nakhonpathom Educational Service Area. Chulalongkorn University:ม.ป.ท.Ploysongsang Panpothong และผู้แต่งคนอื่นๆ. 2006. The understanding and application of the communicative language teaching approach of secondary school teachers in Nakhonpathom Educational Service Area. ม.ป.ท.:Chulalongkorn University;Ploysongsang Panpothong และผู้แต่งคนอื่นๆ. The understanding and application of the communicative language teaching approach of secondary school teachers in Nakhonpathom Educational Service Area. ม.ป.ท.:Chulalongkorn University, 2006. Print.