^Burnet J. (1892) Early Greek Philosophy A. & C. Black, London, OCLC 4365382 (页面存档备份,存于互联网档案馆), and subsequent editions, 2003 edition published by Kessinger, Whitefish, Montana, ISBN 978-0-7661-2826-2
^Kennedy, Edward S., A Survey of Islamic Astronomical Tables, Transactions of the American Philosophical Society, 1956, 46 (2): 123, doi:10.2307/1005726