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
Bayer AM, Danysh HE, Garvich M, Gonzalvez G, Checkley W, Alvarez M, Gilman RH. An unforgettable event: a qualitative study of the 1997-98 El Niño in northern Peru. Disasters. 2014 Apr;38(2):351-74. doi: 10.1111/disa.12046
Fondell E, Balter O, Rothman KJ. Dietary intake and supplement use of vitamins C and E and upper respiratory tract infection. J Am Coll Nutr. 2011 Aug 1;30(4):248-58.