McNeely, Jeffrey A., Kenton R. Miller, Walter V. Reid, Russell A. Mittermeier, and Timothy B. Werner. (1990) 1990. Conserving the World’s Biological Diversity. Gland, Switzerland and Washington, DC: International Union for Conservation of Nature and Natural Resources; World Resources Institute; Conservation International; World Wildlife Fund-US; World Bank. http://www.worldcat.org/oclc/21193600.