A. Boyle (1963) "The Longer Introduction to the Zij-i Ilkhani of Nasir ad-Din Tusi", Journal of Semitic Studies 8(2), pp.244-254
A. Boyle (1963) "The Extended Explanation of the Zij-i Ilkhani by Nasir ad-Din Tusi", Journal of Semitic Studies 8(2), pp.244-254