GER, Joanna. On analytic solutions of the non-linear functional equation. Annales Mathematicae Silesianae, [S. l.], v. 1, p. 103–115, 1985. Disponível em: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14340. Acesso em: 7 may. 2025.