Isangkura, A. (1998). Environment valuation: An entrance fee system for National Parks in Thailand. Economy and Environment Program for Southeast Asia.
Chicago-viite (17. p.)Isangkura, Adis. Environment Valuation: An Entrance Fee System for National Parks in Thailand. Singapore: Economy and Environment Program for Southeast Asia, 1998.
MLA-viite (9. p.)Isangkura, Adis. Environment Valuation: An Entrance Fee System for National Parks in Thailand. Economy and Environment Program for Southeast Asia, 1998.
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