Espaulella J, Guyer H, Diaz-Escriu F, Mellado-Navas JA, Castells M, Pladevall-Vila M. Nutritional supplementation of elderly hip fracture patients. A randomized, double-blind, placebo-controlled trial. Age Ageing. 2000 Sep;29(5):425-31.
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.