Gardner, M. (1988). Riddles of the sphinx: And other mathematical puzzle tales. The Mathematical Association of America.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रGardner, Martin. Riddles of the Sphinx: And Other Mathematical Puzzle Tales. Washington, D.C: The Mathematical Association of America, 1988.
एमएलए (9वां संस्करण) प्रशस्ति पत्रGardner, Martin. Riddles of the Sphinx: And Other Mathematical Puzzle Tales. The Mathematical Association of America, 1988.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.