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
Donnelly DW, Hegarty A, Sharp L, Carsin AE, Deady S, McCluskey N, Comber H, Gavin A. The impact of adjustment for socioeconomic status on comparisons of cancer incidence between two European countries. J Cancer Epidemiol. 2013 Jan 1;2013:612514. doi: 10.1155/2013/612514