Van Brummelen, G. (2013). Heavenly mathematics: The forgotten art of spherical trigonometry. Princeton University Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रVan Brummelen, Glen. Heavenly Mathematics: The Forgotten Art of Spherical Trigonometry. Princeton: Princeton University Press, 2013.
एमएलए (9वां संस्करण) प्रशस्ति पत्रVan Brummelen, Glen. Heavenly Mathematics: The Forgotten Art of Spherical Trigonometry. Princeton University Press, 2013.
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