Canova, L., M. Birchmeier, V. D’Acremont, M. Karly, P. Landry, and B. Genton. “Prevalence Rate and Reasons for Refusals of Influenza Vaccine in Elderly”. Swiss Medical Weekly, vol. 133, no. 4344, Nov. 2003, pp. 598-02, doi:10.4414/smw.2003.10395.