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
Jacquemin B, Schikowski T, Carsin AE, Hansell A, Kramer U, Sunyer J, Probst-Hensch N, Kauffmann F, Kunzli N. The role of air pollution in adult-onset asthma: a review of the current evidence. Semin Resp Crit Care. 2012 Dec;33(6):606-19. doi: 10.1055/s-0032-1325191