of Meeting R. 15th International Conference on Functional Equations and Inequalities, Ustroń, May 19–25, 2013. Ann. Univ. Paedagog. Crac. Stud. Math. [Internet]. 2013 Dec. 31 [cited 2026 Oct. 29];12:91-131. Available from: https://studmath.uken.krakow.pl/article/view/13187