Berry, Wendell. The Unsettling of America
     San Francisco: Sierra Club Books, 1977

Crosby, Alfred. Ecological Imperialism
      New York: Cambridge U.P., 1986

Ehrenfeld, David. The Arrogance of Humanism
     New York: Oxford U.P., 1978

Everndon, Neil. The Natural Alien
     Toronto: University of Toronto Press, 1985

Ponting, Clive. A Green History of the World
     New York: Penguin, 1991

Shepard, Paul. Nature and Madness
     San Francisco: Sierra Club Books, 1982