International Union for Conservation of Nature and Natural Resources United Nations Environment Programme World Wide Fund for Nature text Gland, Switzerland IUCN--the World Conservation Union United Nations Environment Programme World Wide Fund for Nature c1991 monographic iv, 228 p. ; 27 cm. Accompanied by: Summary. 24 p. ; 27 cm. Human ecology Sustainable development Nature conservation Sustainable living 304 IUC 1991 C149 Or. 2831700744