Aissi, Youssef, and Driss Zeglami. “New Pexiderizations of Drygas’ Functional Equation on Abelian Semigroups”. Annales Mathematicae Silesianae 37, no. 2 (August 29, 2023): 169-184. Accessed December 22, 2024. https://journals.us.edu.pl/index.php/AMSIL/article/view/15881.