Ouhabi, Ayoub, et al. “Functional Equations With an Anti-Endomorphism for Functions With Multidimensional Codomains”. Annales Mathematicae Silesianae, vol. 40, no. 1, Dec. 2024, pp. 140-8, https://journals.us.edu.pl/index.php/AMSIL/article/view/18252.