John M. Rassias, M. Arunkumar, E. Sathya and N. Mahesh Kumar (2017) “Generalized Ulam - Hyers stability of on (AQQ): Additive-quadratic-Quartic functional equation”,
Malaya Journal of Matematik
. India, 5(01), pp. 122–142. doi: 10.26637/mjm501/012.