Chaiyanant Panyasiri และผู้แต่งคนอื่นๆ. (2008) Organizational commitment of the staff of the PTT Group. National Institute of Development Administration:ม.ป.ท.Chaiyanant Panyasiri และผู้แต่งคนอื่นๆ. 2008. Organizational commitment of the staff of the PTT Group. ม.ป.ท.:National Institute of Development Administration;Chaiyanant Panyasiri และผู้แต่งคนอื่นๆ. Organizational commitment of the staff of the PTT Group. ม.ป.ท.:National Institute of Development Administration, 2008. Print.