Ajman, H., and Z. Tomac. “Differences in Biological Age of the Best U11 and U13 Teams in Croatia”. Journal of Human Sport and Exercise, vol. 14, no. 5proc, Dec. 2019, pp. S2375-S2379, https://www.jhse.ua.es/article/view/2019-v14-n5-proc-biological-age-best-u11-u13-teams-croatia.