Supattra Sujitwanit. (2009) Circumstances focused on productivity based on company profile /. Kasetsart University,:ม.ป.ท.Supattra Sujitwanit. 2009. Circumstances focused on productivity based on company profile /. ม.ป.ท.:Kasetsart University,;Supattra Sujitwanit. Circumstances focused on productivity based on company profile /. ม.ป.ท.:Kasetsart University, 2009. Print.