[1] R. P. Agarwal, B. Xu and W. Zhang, Stability of functional equations in single variable, J. Math. Anal. Appl. 288(2003), 852-869. 10.1016/j.jmaa.2003.09.032
[5] P. G˘avruta, A generalization of the Hyers-Ulam-Rassias stability of ap- proximately additive mappings, J. Math. Anal. Appl. 184(1994), 431-436. 10.1006/jmaa.1994.1211
[6] K. J. Heuvers, D. S. Moak and B. Boursaw, The functional equation of the square root spiral, In Functional Equations and Inequalities, (Edited by Th. M. Rassias), Kluwer, 2000, pp. 111-117. 10.1007/978-94-011-4341-7_10
[11] S.-M. Jung and P. K. Sahoo, Stability of a functional equation for square root spirals, Appl. Math. Lett. 15(2002), 435-438. 10.1016/S0893-9659(01)00155-0
[12] S.-M. Jung and J. M. Rassias, Stability of general Newton functional equations for logarithmic spirals, Advances in Difference Equations, Vol- ume 2008, Article ID 143053, 5 pages. 10.1155/2008/143053
[13] G. H. Kim, B. Xu and W. Zhang, Notes on stability of the generalized gamma functional equation, Internat. J. Math. Math. Sci. 32(2002), 57-63. 10.1155/S0161171202112129
[14] G. H. Kim, On the Hyers-Ulam-Rassias stability of functional equations in n-variables, J. Math. Anal. Appl. 299(2004), 375-391. 10.1016/j.jmaa.2004.02.064
[16] M. Mirzavaziri and M. S. Moslehian, A fixed point approach to stability of a quadratic equation, Bull. Braz. Math. Soc. 37(3)(2006), 361-376. 10.1007/s00574-006-0016-z
[17] A. K. Mirmostafaee and M. S. Moslehian, Fuzzy versions of Hyers-Ulam- Rassias theorem, Fuzzy Sets and Systems 159(2008), 720-729. 10.1016/j.fss.2007.09.016
[18] M. S. Moslehian, K. Nikodem and D. Popa, Asymptotic aspect of the quadratic functional equation in multi-normed spaces, J. Math. Anal. Appl. 355(2009), 717-724. 10.1016/j.jmaa.2009.02.017
[19] A. Najati and M. B. Moghimi, Stability of a functional equation deriving from quadratic and additive functions in quasi-Banach spaces, J. Math. Anal. Appl. 337(2008), 399-415. 10.1016/j.jmaa.2007.03.104
[22] T. M. Rassias, On the stability of the linear mapping in Banach spaces, Proc. Amer. Math. Soc. 72(1978), 297-300. 10.1090/S0002-9939-1978-0507327-1