Resuming professional football (soccer) during the COVID-19 pandemic in a country with high infection rates: a prospective cohort study - Schumacher, Y. O.; Tabben, M.; Hassoun, K.; Al Marwani, A.; Al Hussein, I.; Coyle, P.; Abbassi, A. K.; Ballan, H. T.; Al-Kuwari, A.; Chamari, K.; Bahr, R. (British Journal of Sports Medicine, 2021)