Pattamaporn Pimthong. (2006) Teaching and learning about matter in grade 6 classrooms : a conceptual change approach /. Kasetsart University,:ม.ป.ท.Pattamaporn Pimthong. 2006. Teaching and learning about matter in grade 6 classrooms : a conceptual change approach /. ม.ป.ท.:Kasetsart University,;Pattamaporn Pimthong. Teaching and learning about matter in grade 6 classrooms : a conceptual change approach /. ม.ป.ท.:Kasetsart University, 2006. Print.