Chatchawan Pluemsumran. (2000) The development of instructional package for teaching group singing prathomsuksa 5 level. Mahidol University,:ม.ป.ท.Chatchawan Pluemsumran. 2000. The development of instructional package for teaching group singing prathomsuksa 5 level. ม.ป.ท.:Mahidol University,;Chatchawan Pluemsumran. The development of instructional package for teaching group singing prathomsuksa 5 level. ม.ป.ท.:Mahidol University, 2000. Print.