No Shock Collar Coalition - http://www.hollysden.com/shock-say_no.htm

Training dogs with help of the shock collar: short and long term behavioural effects - http://www.ust.is/media/ljosmyndir/dyralif/Trainingdogswithshockcollar.pdf

Shock Collars-Why Not? - http://www.cliniciansbrief.com/cms/portals/_default/pdfs/capsules/Aug_04_Cap02.pdf

Can Aggression in Dogs Be Elicited Through the Use of Electronic Pet Containment Systems? - http://www.leaonline.com/doi/abs/10.1207/S15327604JAWS0304_6;jsessionid=niGPVPAUFSvaSL1H7T?cookieSet=1&journalCode=jaws

Dr. Karen Overall on Shock Collars - http://www.joelwalton.com/gpage5.html