Kalinowski, Paweł, Sebastian Kalinowski, Damian Jerszyński, Monika Nowakowska, Jan Konarski, and Dariusz Pietranis. 2019. “The Determinants of footballers’ Effectiveness in a German Club”. Quality in Sport 5 (3):34-42. https://doi.org/10.12775/QS.2019.015.