Thitiroj Rergsumran และผู้แต่งคนอื่นๆ. (2006) Alternative energy : an analysis of natural gas utilization policy implementation. National Institute of Development Administration:ม.ป.ท.Thitiroj Rergsumran และผู้แต่งคนอื่นๆ. 2006. Alternative energy : an analysis of natural gas utilization policy implementation. ม.ป.ท.:National Institute of Development Administration;Thitiroj Rergsumran และผู้แต่งคนอื่นๆ. Alternative energy : an analysis of natural gas utilization policy implementation. ม.ป.ท.:National Institute of Development Administration, 2006. Print.