M. Fortuna, G. Socha, J. Szczurowski, J. Zemełko, and I. Demczyszak, “Comparison of anaerobic efficiency rating in football players groups of age range 12 – 14 and 17 – 18 years based on Wingate test”, J Educ Health Sport, vol. 8, no. 12, pp. 47–58, Dec. 2018.