Wesson, R. L. (2017). Darwin's first theory: Exploring Darwin's quest for a theory of the earth (First Pegasus Books edition.). Pegasus Books.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रWesson, R. L. Darwin's First Theory: Exploring Darwin's Quest for a Theory of the Earth. First Pegasus Books edition. New York: Pegasus Books, 2017.
एमएलए (8वां संस्करण) प्रशस्ति पत्रWesson, R. L. Darwin's First Theory: Exploring Darwin's Quest for a Theory of the Earth. First Pegasus Books edition. Pegasus Books, 2017.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.