ALMIRA, Jose M. On Popoviciu-Ionescu functional equation. Annales Mathematicae Silesianae, [S. l.], v. 30, p. 5–15, 2016. Disponível em: https://journals.us.edu.pl/index.php/AMSIL/article/view/13953. Acesso em: 8 apr. 2025.