Pattippa Saengpitak และ Sunait Chutintaranond. (2006) Change in the perception of the Naga fireballs : a case study of Amphoe Phon Pisai, Changwat Nong Khai. Chulalongkorn:ม.ป.ท.Pattippa Saengpitak และ Sunait Chutintaranond. 2006. Change in the perception of the Naga fireballs : a case study of Amphoe Phon Pisai, Changwat Nong Khai. ม.ป.ท.:Chulalongkorn;Pattippa Saengpitak และ Sunait Chutintaranond. Change in the perception of the Naga fireballs : a case study of Amphoe Phon Pisai, Changwat Nong Khai. ม.ป.ท.:Chulalongkorn, 2006. Print.