1. Berggren, J.L. 1980. “A Comparison of Four Analemmas for Determining the Azimuth of the Qibla”. Journal for the History of Arabic Science 4(1): 69–80.
2. Berggren, J.L. 1987. “Spherical Trigonometry in the Zīj of Kūshyār ibn Labbān”. In Festschrift: A volume of studies of the history of science in the near east, Dedicated to E. S. Kennedy, ed. D. A. King and G. Saliba. New York: New York Academy of Sciences. (An English translation of the section in the zīj dealing with spherical trigonometry).
3. Bīrūnī, Abū al-Rayḥān. 1967. The determination of the coordinates of cities (transl: J. Ali). Beirut: American University of Beirut.
4. Debarnot, M-Th. 1978. “Introduction du Triangle Polaire par Abū Naṣr b. ‘Irāq”. Journal for the History of Arabic Science 2(1): 126–136.
5. Hilbert, D., and S. Cohn-Vossen. 1952. Geometry and the Imagination. New York: Chelsea.