Higgins, P. M. (2008). Number story: From counting to cryptography. Copernicus Books.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHiggins, Peter M. Number Story: From Counting to Cryptography. London: Copernicus Books, 2008.
एमएलए (9वां संस्करण) प्रशस्ति पत्रHiggins, Peter M. Number Story: From Counting to Cryptography. Copernicus Books, 2008.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.