@article{GDZPPN00204241X, title = {On Hyers-Ulam stability for a class of functional equations.}, journal = {Aequationes mathematicae}, volume = {53}, year = {1997}, pages = {74-86}, zbl = {0879.39009}, url = {http://dml.mathdoc.fr/item/GDZPPN00204241X} }
Borelli, Costanza. On Hyers-Ulam stability for a class of functional equations.. Aequationes mathematicae, Tome 53 (1997) pp. 74-86. http://gdmltest.u-ga.fr/item/GDZPPN00204241X/