Dobosz-Smela, Marta, and Marek Cezary Zdun. “On Involutions Satisfying a System of Functional Equations”. Annales Mathematicae Silesianae 14 (July 23, 2022): 41–50. Accessed December 5, 2025. https://journals.us.edu.pl/index.php/AMSIL/article/view/14126.