1. Aggarwal, M., and S. Ghosh. 2020. India’s Environment Ministry Unlocked Many Protected Areas During the Lockdown. Science-The Wire: https://science.thewire.in/environment/indias-environment-ministry-unlocked-many-protected-areas-during-the-lockdown/.
2. Ahmad, S. A. 2009. Visitors’ Willingness to pay for an Entrance fee: A Case Study of Marine Parks in Malaysia. (Doctoral Thesis). University of Glasgow, Scotland. https://core.ac.uk/download/pdf/293036873.pdf.
3. The pricing of protected areas in nature-based tourism: A local perspective
4. A contingent valuation study of scuba diving benefits: Case study in Mu Ko Similan Marine National Park, Thailand
5. Ayers, J., and F. Launay. 2021. Conservation after coronavirus: We need to diversify and innovate (commentary). Mongabay. https://news.mongabay.com/2021/09/after-coronavirus-conservation-needs-diversification-and-innovation-commentary/.