Effects of the `11+ Kids` injury prevention programme on severe injuries in children`s football: a secondary analysis of data from a multicentre cluster-randomised controlled trial - Beaudouin, F.; Rössler, R.; aus der Fünten, K.; Bizzini, M.; Chomiak, J.; Verhagen, E.; Junge, A.; Dvorak, J.; Lichtenstein, E.; Meyer, T.; Faude, O. (British Journal of Sports Medicine, 2019)