Aissi, Youssef, Driss Zeglami, and Brahim Fadli. “Alienation of Drygas’ and Cauchy’s Functional Equations”. Annales Mathematicae Silesianae 35, no. 2 (April 13, 2021): 131–148. Accessed February 5, 2026. https://journals.us.edu.pl/index.php/AMSIL/article/view/13440.