Pratt. Archives of American Time. University of Pennsylvania Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रPratt. Archives of American Time. University of Pennsylvania Press.
एमएलए (9वां संस्करण) प्रशस्ति पत्रPratt. Archives of American Time. University of Pennsylvania Press.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.