Merrill RM, Kelley TA, Cox E, Layman AB, Layton BJ, Lindsay R. Factors and barriers influencing influenza vaccination among students at Brigham Young University. Med Sci Monit. 2010 Feb;16(2):PH29-34.
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.