1 2 Baroni, Helen Josephine (2002). The illustrated encyclopedia of Zen Buddhism. New York: Rosen Pub. Group. p. 100. ISBN0-8239-2240-5.
Mark and Luebeck,Walter Hosak (2006). Big Book of Reiki Symbols, The. Tokyo: Lotus Press. ISBN0-914955-64-0.
D. D. Jc Husfelt (2006). The Return of the Feathered Serpent Shining Light of 'First Knowledge': Survival and Renewal at the End of an Age, 2006-2012. Authorhouse. ISBN1-4259-0546-3.