1. A Delicate Arrangement: The Strange Case of Charles Darwin and Alfred Russel Wallace; Times Books: New York, 1980;
2. Just Before the Origin: Alfred Russel Wallace's Theory of Evolution; Columbia University Press: New York, 1984;
3. Ed. Infinite Tropics: An Alfred Russel Wallace Anthology; Verso Press: London, 2002.
4. Alfred Russel Wallace, A Life; Princeton University Press: Princeton, NJ, 2001;
5. In Darwin's Shadow: The Life and Science of Alfred Russel Wallace: A Biographical Study on the Psychology of History; Oxford University Press: New York, 2002;