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.
Citazione stile Chigago Style (17a edizione)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, e Joan Gibb Engel. Ethics of Environment and Development: Global Challenge, International Response. Tucson: University of Arizona Press, 1990.
Citatione MLA (9a 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.