Górowski, J., and A. Łomnicki. “Quasi-Arithmetic Means”. Annales Universitatis Paedagogicae Cracoviensis | Studia Ad Didacticam Mathematicae Pertinentia, vol. 7, July 2017, pp. 35-43, https://didacticammath.uken.krakow.pl/article/view/3628.