McDonald R, Mead N, Cheraghi-Sohi S, Bower P, Whalley D. Governing the ethical consumer: identity, choice and the primary care medical encounter. Sociol Health Illn. 2007 Apr 1;29(3):430-56.
Rothman KJ. Computation of exact confidence intervals for the odds ratio. Int J Biomed Comput. 1975 Jan;6(1):33-9.
Rothman KJ. Computer analysis for case-control studies with individual matching. Int J Biomed Comput. 1974 Oct;5(4):241-7.