Burkhardt, R. W. Darwin on animal behavior and evolution: Richard W. Burkhardt. The Darwinian heritage : [incl. proceed. of the Charles Darwin Centenary Conference, Florence Center for the History and Philosophy of Science, June 1982].(1985).
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रBurkhardt, Richard W. "Darwin on Animal Behavior and Evolution: Richard W. Burkhardt." The Darwinian Heritage : [incl. Proceed. of the Charles Darwin Centenary Conference, Florence Center for the History and Philosophy of Science, June 1982].(1985) .
एमएलए (8वां संस्करण) प्रशस्ति पत्रBurkhardt, Richard W. "Darwin on Animal Behavior and Evolution: Richard W. Burkhardt." The Darwinian Heritage : [incl. Proceed. of the Charles Darwin Centenary Conference, Florence Center for the History and Philosophy of Science, June 1982].(1985), .