The UEFA Heading Study: Heading incidence in children's and youth' football (soccer) in eight European countries - Beaudouin, F.; Gioftsidou, A.; Larsen, M. N.; Lemmink, K.; Drust, B.; Modena, R.; Ramos Espinola, J.; Meiu, M.; Vouillamoz, M.; Meyer, T. (Scandinavian Journal of Medicine & Science in Sports, 2020)