Biblio

IUCN -Gland, CH, International Union for Conservation of Nature, Gland, C. H. W. W. F. -, and Nairobi, K. E. U. N. E. P. -, Caring for the earth : a strategy for sustainable living. Gland, Switzerland: IUCN - International Union for Conservation of Nature, 1991, p. iv, 228 p.

IUCN -Gland, CH, International Union for Conservation of Nature, Gland, C. H. W. W. F. -, and Nairobi, K. E. U. N. E. P. -, “World conservation strategy for the 1990s”. World Conservation Union (IUCN), Gland, Switzerland, p. vi, 160 p.: tab., 1989.