Economic Valuation of the Environment and the Travel Cost Approach: The Case of Ayubia Natioanl Park. The Pakistan Development Review, [S. l.], v. 42, n. 4II, p. pp.537–551, 2022. DOI: 10.30541/v42i4IIpp.537-551. Disponível em: https://thepdr.pk/index.php/pdr/article/view/1921. Acesso em: 8 jun. 2025.