"canon." The Columbia Electronic Encyclopedia, Sixth Edition. Columbia University Press., 2003. Answers.com 17 Jun. 2009. http://www.answers.com/topic/canon
"Canon law." Encyclopedia of the Early Modern World. The Gale Group, Inc, 2004. Answers.com 17 Jun. 2009.
canonlaw.info
Edward Peters: Canon Law canonlaw.info. (englanniksi)
Kuzhinapurath, Thomas: Salvific Law: Salvific Character of CCEO, An Historical Overview, s. 81–84. Trivandrum,Kerala, India: M.S. Publications, 2008. Teoksen verkkoversio (viitattu 24.6.2009). (englanniksi)
tufts.edu
perseus.tufts.edu
Greek Word Study ToolPerseus 4.0. Perseus Digital Library Project. Viitattu 22.2.2018.