[1] A. Bahraini, G. Askari, M. Eshaghi Gordji, and R. Gholami, Stability and hyperstability of orthogonally ∗-mhomomorphisms in orthogonally lie c
∗
-algebras: a fixed point approach, J. Fixed Point Theory Appl. 20 (2018),
89.
[2] J.A. Baker, The stability of the cosine equation, Proc. Amer. Math. Soc. 80 (1980), no. 3, 411–416.
[3] J.B. Diaz and B. Margolis, A fixed point theorem of the alternative, for contractions on a generalized complete
metric space, Bull. Amer. Math. Soc. 74 (1968), no. 2, 305–309.
[4] P. Gˇavruta, A generalization of the hyers-ulam-rassias stability of approximately additive mappings, J. Math.
Anal. Appl. 184 (1994), no. 3, 431–436.
[5] M. Eshaghi Gordji, Z. Alizadeh, H. Khodaei, and C. Park, On approximate homomorphisms: a fixed point
approach, Math. Sci. 6 (2012), 59.
[6] M. Eshaghi Gordji and H. Khodaei, Solution and stability of generalized mixed type cubic, quadratic and additive
functional equation in quasi-Banach spaces, Nonlinear Anal. 71 (2009), 5629–5643.
[7] M. Eshaghi Gordji, M. Rameani, M.D.L. Sen, and Y.J. Cho, On orthogonal sets and Banach fixed point theorem,
Fixed Point Theory 18 (2018), no. 2, 569–578.
[8] N. Haokip and N. Goswami, Stability of an additive and quadratic functional equations, Adv. Math. Sci. J. 9
(2020), no. 10, 8443–8554.
[9] D.H. Hyers, On the stability of the linear functional equation, Proc. Nat. Acad. Sci. United States of America 27
(1941), no. 4, 222–224.
[10] K.W. Jun and H.M. Kim, The generalized Hyers-Ulam-Rassias stability of a cubic functional equation, J. Math.
Anal. Appl. 274 (2002), no. 2, 867–878.
[11] K.W. Jun, H.M. Kim, and I.S. Chang, On the Hyers-Ulam stability of an Euler-Lagrange type cubic functional
equation, J. Comput. Anal. Appl. 7 (2005), no. 1, 21–33.
[12] K.W. Jun, S.B. Lee, and W.G. Park, Solution and stability of a cubic functional equation, Acta Math. Sinica,
English Ser. 26 (2010), no. 7, 1255–1262.
[13] M.A. Khamsi and W.A. Kirk, An introduction to metric spaces and fixed point theory, John Wiley & Sons, 2011.[14] H. Khodaei, On the stability of additive, quadratic, cubic and quartic set-valued functional equations, Results
Math. 1 (2015), no. 68, 1–10.
[15] A. Najati, The generalized Hyers-Ulam-Rassias stability of a cubic functional equation, Turk. J. Math. 31 (2007),
no. 4, 395–408.
[16] A. Najati and F. Moradlou, Stability of an Euler-Lagrange type cubic functional equation, Turk. J. Math. 33
(2009), no. 1, 65–73.
[17] C. Park, Y. J. Cho, and J. R. Lee, Orthogonal stability of functional equations with the fixed point alternative,
Adv. Differ. Equ. 2012 (2012), no. 1, 173.
[18] T.M. Rassias, On the stability of the linear mapping in Banach spaces, Proc. Amer. Math. Soc. 72 (1978), no. 2,
297–300.
[19] T.M. Rassias and P. Semrl, ˇ On the Hyers-Ulam stability of linear mappings, J. Math. Anal. Appl. 173 (1993),
no. 2, 325–338.
[20] F. Skof, Proprieta’locali e approssimazione di operatori, Rend. Sem. Mat. Fis. Milano 53 (1983), no. 1, 113–129.