[7] Kubo T, Shoji Y, Tsuge T et al. Voluntary contributions to hiking trail maintenance: Evidence from a field experiment in a national park, Japan[J]. Ecological economics, 144, 124-128(2018).
[8] Pascoe S, Doshi A, Thébaud O et al. Estimating the potential impact of entry fees for marine parks on dive tourism in South East Asia[J]. Marine Policy, 47, 147-152(2014).
[10] Crandall D A, Driver B L. Recreation on public lands: Should the user pay?[J]. American Forests, 90, 10-11(1984).
[11] More T A. A functionalist approach to user fees[J]. Journal of Leisure Research, 31, 227-244(1999).
[12] Lee C K, Han S Y. Estimating the use and preservation values of national parks’ tourism resources using a contingent valuation method[J]. Tourism Management, 23, 531-540(2002).
[13] Pandit R, Dhakal M, Polyakov M. Valuing access to protected areas in Nepal: The case of Chitwan National Park[J]. Tourism Management, 50, 1-12(2015).
[14] Lal P, Wolde B, Masozera M et al. Valuing visitor services and access to protected areas: The case of Nyungwe National Park in Rwanda[J]. Tourism Management, 61, 141-151(2017).
[15] Nyaupane G P, Graefe A R, Burns R C. The role of equity, trust and information on user fee acceptance in protected areas and other public lands: A structural model[J]. Journal of Sustainable Tourism, 17, 501-517(2009).
[16] Reynisdottir M, Song H, Agrusa J. Willingness to pay entrance fees to natural attractions: An Icelandic case study[J]. Tourism Management, 29, 1076-1083(2008).
[17] Mayer M, Woltering M. Assessing and valuing the recreational ecosystem services of Germany’s national parks using travel cost models[J]. Ecosystem Services, 31, 371-386(2018).
[19] Thur S M. User fees as sustainable financing mechanisms for marine protected areas: An application to the Bonaire National Marine Park[J]. Marine Policy, 34, 63-69(2010).
[20] Mitchell R C, Carson R T. Using surveys to value public goods: The contingent valuation method[J]. Land Economics, 72, 249-250(1990).
[21] Wang P W, Jia J B. Tourists’ willingness to pay for biodiversity conservation and environment protection, Dalai Lake protected area: Implications for entrance fee and sustainable management[J]. Ocean & Coastal Management, 62, 24-33(2012).
[22] Platania M, Rizzo M. Willingness to pay for protected areas: A case of Etna Park[J]. Ecological Indicators, 93, 201-206(2018).
[23] Bigerna S, Micheli S, Polinori P. Willingness to pay for electric boats in a protected area in Italy: A sustainable tourism perspective[J]. Journal of Cleaner Production, 224, 603-613(2019).
[24] Kaffashi S, Yacob M R, Clark M S et al. Exploring visitors’ willingness to pay to generate revenues for managing the National Elephant Conservation Center in Malaysia[J]. Forest Policy and Economics, 56, 9-19(2015).