Sirapatsorn Wongthongdee และผู้แต่งคนอื่นๆ. (2007) The study on relationship of human resource development knowledge and understanding, internal organizational factors, roles and competencies of HRD professionals in the Thai Civil Service. National Institute of Development Administration:ม.ป.ท.Sirapatsorn Wongthongdee และผู้แต่งคนอื่นๆ. 2007. The study on relationship of human resource development knowledge and understanding, internal organizational factors, roles and competencies of HRD professionals in the Thai Civil Service. ม.ป.ท.:National Institute of Development Administration;Sirapatsorn Wongthongdee และผู้แต่งคนอื่นๆ. The study on relationship of human resource development knowledge and understanding, internal organizational factors, roles and competencies of HRD professionals in the Thai Civil Service. ม.ป.ท.:National Institute of Development Administration, 2007. Print.