Brooks, J. L. (1984). Just before the origin: Alfred Russel Wallace's theory of evolution. Columbia University Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रBrooks, John Langdon. Just Before the Origin: Alfred Russel Wallace's Theory of Evolution. New York: Columbia University Press, 1984.
एमएलए (9वां संस्करण) प्रशस्ति पत्रBrooks, John Langdon. Just Before the Origin: Alfred Russel Wallace's Theory of Evolution. Columbia University Press, 1984.
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