Bourne JE, Sauchelli S, Perry R, Page A, Leary S, England C, Cooper AR. Health benefits of electrically-assisted cycling: a systematic review. Int J Behav Nutr Phy. 2018 Nov 21;15(1):116. doi: 10.1186/s12966-018-0751-8
Jeuland M, Maskery B, Cook J, Poulos C, Clemens J, Lauria D, Stewart J, Lucas M, Whittington D. Incorporating cholera vaccine herd protection into economic cost-benefit and cost-effectiveness models. Procedia Vaccinol. 2010;2(2010):140-6. doi: 10.1016/j.provac.2010.07.006