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
Hayes AF, Montoya AK, Rockwood NJ. The analysis of mechanisms and their contingencies: PROCESS versus structural equation modeling. AMJ. 2017 Feb;25(1):76-81. doi: 10.1016/j.ausmj.2017.02.001