1. Hypothesis formulation for scientific investigation of vertebral subluxation;Owens;J Vertebral Subluxation Res,1999
2. Essential principles of chiropractic;Strang,1984
3. Association of Chiropractic Colleges. Position statement. July 1996. Available at http://www.chirocolleges.org/. Accessed January 13, 2004
4. Operational definitions of vertebral subluxation;Owens;Top Clin Chiropr,2001
5. An introduction to and explanation of chiropractic science and theory;Williams;Chiropr Res J,2000