1. Abell, L., Bromham, I., 2009. The Value of the Watersports Economy in North Devon, July 2009, 77 pp.
2. Priceless. On Knowing the Price of Everything and the Value of Nothing;Ackermann,2004
3. Appledore Arts, 2010. 〈http://www.appledorearts.org/index.htm〉 (accessed 9.12.10).
4. The Economics of Biodiversity and Ecosystems: Scoping the Science;Balmford,2008
5. Quantifying the evidence for biodiversity effects on ecosystem functioning and services;Balvanera;Ecol. Lett.,2006