Suchitra Panyadilok และ Prathurng Hongsranagon. (2011) Factors influencing quality of life of elders in Chiang Khwan district, Roi Et province, Thailand. Chulalongkorn University:ม.ป.ท.Suchitra Panyadilok และ Prathurng Hongsranagon. 2011. Factors influencing quality of life of elders in Chiang Khwan district, Roi Et province, Thailand. ม.ป.ท.:Chulalongkorn University;Suchitra Panyadilok และ Prathurng Hongsranagon. Factors influencing quality of life of elders in Chiang Khwan district, Roi Et province, Thailand. ม.ป.ท.:Chulalongkorn University, 2011. Print.