56-57. 24 See, F.A. Shamsî, "Abu al-Rayhân Muhammad ibn Ahmad al-Bayrûnî", Al-Bîrûnî Commemorative Volume: Proceedings of the International Congress Held in Pakistan, November 26 Through December 12, 1973, Karachi 1979, pp. 260-288. 25 See, W. Barthold, Turkestan v ...