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
Sorensen HT, Steffensen FH, Sabroe S, Rothman KJ, Gillman MW, Fischer P. Historical cohort study of in utero exposure to uterotonic drugs and cognitive function in young adult life. West J Med. 1999 Jan 1;170(5):260-2.