Porter, D. M. The "beagle" collector and his collections: Duncan M. Porter. 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 पत्रPorter, Duncan M. "The "Beagle" Collector and His Collections: Duncan M. Porter." 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 पत्रPorter, Duncan M. "The "Beagle" Collector and His Collections: Duncan M. Porter." The Darwinian Heritage : [incl. Proceed. of the Charles Darwin Centenary Conference, Florence Center for the History and Philosophy of Science, June 1982].(1985), .