Vinceti M, Balboni E, Rothman KJ, Teggi S, Bellino S, Pezzotti P, Ferrari F, Orsini N, Filippini T. Substantial impact of mobility restrictions on reducing COVID-19 incidence in Italy in 2020. J Travel Med. 2022 Sep;29(6):taac081. doi: 10.1093/jtm/taac081
Fondell E, Lagerros YT, Sundberg CJ, Lekander M, Balter O, Rothman KJ, Balter K. Physical activity, stress, and self-reported upper respiratory tract infection. Med Sci Sports Exerc. 2011 Feb 1;43(2):272-9.