International Union for Conservation of Nature and Natural Resources. Ethics Working Group, Conference on Conservation and Development: Implementing the World Conservation Strategy (1986 : Ottawa, Ont.), Engel, J. R., & Engel, J. G. (1990). Ethics of environment and development: Global challenge, international response. University of Arizona Press.
Citace podle Chicago (17th ed.)International Union for Conservation of Nature and Natural Resources. Ethics Working Group, Ont.) Conference on Conservation and Development: Implementing the World Conservation Strategy (1986 : Ottawa, J. Ronald Engel, a Joan Gibb Engel. Ethics of Environment and Development: Global Challenge, International Response. Tucson: University of Arizona Press, 1990.
Citace podle MLA (9th ed.)International Union for Conservation of Nature and Natural Resources. Ethics Working Group, et al. Ethics of Environment and Development: Global Challenge, International Response. University of Arizona Press, 1990.