Phumsathan S. Environmental Value Orientation and Environmental Impact Perception of Visitors to Khao Yai National Park. kasetsart J. Soc. Sci. [internet]. 2013 Dec. 31 [cited 2026 Sep. 12];34(3):534-42. available from: https://so04.tci-thaijo.org/index.php/kjss/article/view/247110