Anderson, R.S. and Carpenter, S.L. 1991. Vegetation change in Yosemite Valley, Yosemite National Park, California, during the Protohistoric Period. Armstrong, S. 1991. Okavango survives near-fatal fright. Ashford, J. 1991.
Japan chips away at Chile's forests.
South Pacific Conservation Programme. World Wide Fund for Nature, Gland, Switzerland. Baldock, D. 1989. Agriculture and Habitat Loss in Europe . WWF International, Gland, Switzerland.