Elqorachi, E. and Redouani, A. (2017) “Solutions and stability of generalized Kannappan’s and Van Vleck’s functional equations”, Annales Mathematicae Silesianae, 32, pp. 169–200. Available at: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/13919 (Accessed: 7 May 2025).