Bowlby, John. Charles Darwin: A New Life. W. W. Norton: New York, 1990.

Darwin, Charles. The Origin of Species. Bantam: New York, 1999.

–-––. The Expression of the Emotions in Man and Animals. University of Chicago Press: Chicago, 1965.

–––. Autobiography. W. W. Norton: New York, 1958.

Desmond, Adrian, and James Moore. Darwin. Michael Joseph: London, 1991.

Popular pages: Charles Darwin