Kapstein, Matthew (1992). "Samantabhadra and Rudra: Innate Enlightenment and Radical Evil in Tibetan Rnying-ma-pa Buddhism". In Frank E. Reynolds and David Tracy (eds) (1992). Discourse and Practice. Albany: SUNY Press. Source: [1] (accessed: Friday March 26, 2010), p.64
rigpawiki.org
Rigpa Shedra Wiki (July, 2009). "Eight doors of spontaneous presence." Source: [2] (accessed: Sunday April 4, 2010)
