Eshaghi Gordji, Madjid, and N. Ghobadipour. 2011. “Generalized Ulam—Hyers Stabilities of Quartic Derivations on Banach Algebras”. Proyecciones (Antofagasta, On Line) 29 (3):209-26. https://doi.org/10.4067/S0716-09172010000300005.