Pongsan Sanyakamdhorn และ Udomsak Seenprachawong. (2017) Valuing cultural heritage: a contingent valuation study of temples in Chiang Saen. National Institute of Development Administration:ม.ป.ท.Pongsan Sanyakamdhorn และ Udomsak Seenprachawong. 2017. Valuing cultural heritage: a contingent valuation study of temples in Chiang Saen. ม.ป.ท.:National Institute of Development Administration;Pongsan Sanyakamdhorn และ Udomsak Seenprachawong. Valuing cultural heritage: a contingent valuation study of temples in Chiang Saen. ม.ป.ท.:National Institute of Development Administration, 2017. Print.