↑Lopez Jr., Donald S. (2001). The Story of Buddhism: A Concise Guide to its History and Teachings. New York, USA: HarperSanFrancisco. ISBN0-06-069976-0 (cloth) P.260.
↑Keown, Damien (editor) with Hodge, Stephen; Jones, Charles; Tinti, Paola (2003). A Dictionary of Buddhism. Oxford, UK: Oxford University Press. ISBN0-19-860560-9 p.172.