Linton (2004), p.97). Owing to the unreliability of the data al-Zarqali relied on for this estimate, its remarkable accuracy was fortuitous. Linton, Christopher M. (2004). From Eudoxus to Einstein—A History of Mathematical Astronomy. Cambridge University Press. ISBN978-0-521-82750-8.
doi.org
Hogendijk, Jan P.; Berggren, J. L. (1989). "Episodes in the Mathematics of Medieval Islam by J. Lennart Berggren". Journal of the American Oriental Society. 109 (4): 697–698. doi:10.2307/604119. JSTOR604119.
Hogendijk, Jan P.; Berggren, J. L. (1989). "Episodes in the Mathematics of Medieval Islam by J. Lennart Berggren". Journal of the American Oriental Society. 109 (4): 697–698. doi:10.2307/604119. JSTOR604119.