New challenges for the world's protected area system : proceedings of the 30th Working Session of the IUCN's Commission on National Parks and Protected Areas, San José, Costa Rica, 30-31 January 1988

New challenges for the world's protected area system : proceedings of the 30th Working Session of the IUCN's Commission on National Parks and Protected Areas, San José, Costa Rica, 30-31 January 1988

Publication
1988
Authors
Thorsell, J. W.