Górowski, Jan, and Adam Łomnicki. “O średnich”. Annales Universitatis Paedagogicae Cracoviensis | Studia ad Didacticam Mathematicae Pertinentia 3 (July 26, 2017): 56–66. Accessed May 21, 2024. https://didacticammath.uken.krakow.pl/article/view/3764.