Werawat Punnitamai. (2012) Developing causal relationship models of HR roles and competencies on their professionalism among Thai HR in public and private organizations. <i>NIDA Development Journal</i>, <i>52</i>(3), 97-128.Werawat Punnitamai. "Developing causal relationship models of HR roles and competencies on their professionalism among Thai HR in public and private organizations". NIDA Development Journal 52 (2012):97-128.Werawat Punnitamai. Developing causal relationship models of HR roles and competencies on their professionalism among Thai HR in public and private organizations. National Institute of Development Administration:ม.ป.ท. 2012.