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
Forns J, Vegas O, Julvez J, Garcia-Esteban R, Rivera M, Lertxundi N, Guxens M, Fano E, Ferrer M, Grellier J, Ibarluzea J, Sunyer J. Association between child cortisol levels in saliva and neuropsychological development during the second year of life. Stress Health. 2014 Apr;30(2):142-8. doi: 10.1002/smi.2504
Urrutia I, Aguirre U, Sunyer J, Plana E, Muniozguren N, Martinez-Moratalla J. Changes in the prevalence of asthma in the Spanish cohort of the European Community Respiratory Health Survey (ECRHS-II). Arch. Bronconeumol. 2007 Aug;43(8):425-30.