Não informado. (2007). Report of the Penrose Research Laboratory. Zoological Society of Philadelphia.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Report of the Penrose Research Laboratory. Philadelphia, Pa: Zoological Society of Philadelphia, 2007.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Report of the Penrose Research Laboratory. Zoological Society of Philadelphia, 2007.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.