IUCN yearbook : annual report of the International Union for Conservation of Nature and Natural Resources for 1971 1972
IUCN yearbook : annual report of the International Union for Conservation of Nature and Natural Resources for 1970 1971
Director-General's report on the work of the Union since the 16th session of the IUCN General Assembly held in Madrid, November 1984 : triennial report 1985-1987 1987
