Čillík, I., R. Kollár, J. Kremnický, P. Pivovarniček, and M. Mandzáková. “The Level of General Physical Performance and Physical Development of 7 and 10-Year-Old Boys and Girls”. Journal of Human Sport and Exercise, vol. 10, no. 1proc, Sept. 2021, pp. S259-S268, doi:10.14198/jhse.2015.10.Proc1.13.