Cichoń, D. (2014) “À la recherche de la preuve perdue: a simple proof of the Ficken theorem”, Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, 13, pp. 133–137. Available at: https://studmath.uken.krakow.pl/article/view/13198 (Accessed: 29 October 2026).