Barcz, Eugeniusz. “Fixed Point Theorems of Contraction Type Mappings and Some of Their Applications in Fractal Geometry”. Annales Universitatis Paedagogicae Cracoviensis | Studia ad Didacticam Mathematicae Pertinentia 13 (December 31, 2021): 29–42. Accessed May 2, 2024. https://didacticammath.uken.krakow.pl/article/view/8473.