Serey และ Pen Sok. (1994) A focus group study of health education model on primary health care in Surin province, Thailand. Mahidol University,:ม.ป.ท.Serey และ Pen Sok. 1994. A focus group study of health education model on primary health care in Surin province, Thailand. ม.ป.ท.:Mahidol University,;Serey และ Pen Sok. A focus group study of health education model on primary health care in Surin province, Thailand. ม.ป.ท.:Mahidol University, 1994. Print.