Shvidenko, A., Barber, C.V., Persson, R., Gonzalez, P., Hassan, R., Lakyda, P., McCallum, I., Nilsson, S., Pulhin, J., van Rosenburg, B. and Scholes, R. (2005). Chapter 21: Forest and Woodland Systems. In: Millennium Ecosystem Assessment - Ecosystems and Human Well-being: Current State and Trends. pp.585-621 – Accessed 19th May 2017.
 UN FAO. (2007). The State of Food and Agriculture 2007: Paying Farmers for Environmental Services. Food and Agricultural Organization of the United Nations, Rome – Accessed 19th May 2017.
 Pfaff, A., Kerr, S., Lipper, L., Cavatassi, R., Davis, B., Hendy, J. and Sanchez, A. (2007). Will buying tropical forest carbon benefit the poor? Evidence from Costa Rica. Land Use Policy 24(3): 600–610.
 Wünscher, T., Engel, S. and Wunder, S. (2006). Payments for environmental services in Costa Rica: increasing efficiency through spatial differentiation. Quarterly Journal of International Agriculture 45(4): 319-337.
 OECD. (2010). Paying for biodiversity: enhancing the cost-effectiveness of payments for ecosystem services. OECD: Paris.
 Funk, J. (2006). Maori farmers look to environmental markets in New Zealand. Ecosystem Marketplace, 24th January 2006 – Accessed 19th May 2017.
 Natural Capital Committee. (2015). Protecting and Improving Natural Capital for Prosperity and Wellbeing: Third ‘State of Natural Capital’ report. Natural Capital Committee, HM Government, London – Accessed 19th May 2017.
 HM Government. (2015). The government’s response to the Natural Capital Committee’s third State of Natural Capital report, September 15 – Accessed 19th May 2017.
 United Nations. (2014). FORESTS New York Declaration on Forests Action Statements and Action Plans – Accessed 19th May 2017.
 IUCN. (2016). The Bonn Challenge. IUCN – Accessed 19th May 2017.