[1] Badora R. On the stability of cosine functional equation. Wyzszkola Red Krakow Rocz Nauk-Dydakt Pr Mat, 1998, 15: 1-14
[2] Badora R. On the stability of a functional equation for generalized trigonometric functions//Rassias Th M, ed. Functional Equations and Inequalities. Kluwer Academic Publishers, 2000: 1-5
[3] Badora R. Note on the superstability of the Cauchy functional equation. Pub Math Debrecen, 2000, 57(3/4): 421-424
[4] Baker J A. The stability of the cosine equation. Proc Amer Math Soc, 1980, 80: 411-416
[5] Baker J A, Lawrence J, Zorzitto F. The stability of the equation f(x+y)=f(x)f(y). Proc Amer Math Soc, 1979, 74: 242-246
[6] Bouikhalene B, Elqorachi E, Rassias J M. The superstability of d'Alembert's functional equation on the Heisenberg group. Appl Math Lett, 2010, 23(1): 105-109
[7] Bouikhalene B, Elqorachi E. Stability of a generalization Wilson's equation. Aequat Math, 2015, DOI: 10-1007/s00010-015-0356-0
[8] Bouikhalene B, Elqorachi E. Stability of the spherical functions. Georgian Math J, (to appears)
[9] Chung J, Sahoo P K. Stability of Wilson's functional equations with involutions. Aequat Math, 2015, 89(3): 749-763
[10] D'Alembert, Jean Le Round. Addition au Mémoire sur la courbe que forme une corde tendue mise en vibration. Hist Acad Berlin, 1750: 355-360
[11] Davison T M K. D'Alembert's functional equation on topological groups. Aequat Math, 2008, 76: 33-53
[12] Davison T M K. D'Alembert's functional equation on topological monoids. Publ Math Debrecen, 2009, 75(1/2): 41-66
[13] Ebanks Bruce R, Stetkær H. On Wilson's functional equations. Aequat Math, 2015, 89(2): 339-354
[14] Elqorachi E, Akkouchi M. On generalized d'Alembert and Wilson functional equations. Aequat Math, 2003, 66(3): 241-256
[15] Elqorachi E, Akkouchi M. The superstability of the generalized d'Alembert functional equation. Georgian Math J, 2003, 10: 503-508
[16] Ger R. Superstability is not natural. Rocznik Nauk-Dydakt Prace Mat, 1993, 159(13): 109-123
[17] Hyers, D. H. On the stability of the linear functional equation. Proc Nat Acad Sci, 1941, 27: 222-224
[18] Kannappan Pl. The functional equation f(xy)+f(xy-1)=2f(x)f(y) for groups. Proc Amer Math Soc, 1968, 19: 69-74
[19] Kannappan Pl, Kim G H. On the stability of the generalized cosine functional equations. Stud Math Ann Acad Paedagogicae Cracowiensis, 2001, 4: 49-57
[20] Kim G H. The stability of d'Alembert and Jensen type functional equations. J Math Anal Appl, 2007, 325: 237-248
[21] Kim G H. On the stability of trigonometric functional equations. Adv Differ Equ, 2007, 2007: Article ID 90405
[22] Kim G H. On the stability of the Pexiderized trigonometric functional equation. Appl Math Comput, 2008, 203(1): 99-105
[23] Lukasik R. Some generalization of the quadratic and Wilson's functional equation. Aequat Math, 2014, 87(1/2): 105-123
[24] Rassias J M. On approximation of approximately linear mappings by linear mappings. J Funct Anal, 1982, 46: 126-130
[25] Rassias Th M. On the stability of linear mapping in Banach spaces. Proc Amer Math Soc, 1978, 72: 297-300
[26] Redouani A, Elqorachi E, Rassias Th M. The superstability of d'Alembert's functional equation on step 2 nilpotent groups. Aequat Math, 2007, 74(3): 226-241
[27] Stetkær H. Functional Equations on Groups. Singapore: World Scientific, 2013
[28] Stetkær H. D'Alembert's functional equation on groups. Banach Center Publ, 2013, 99: 173-191
[29] Stetkær H. A link between Wilson's and d'Alembert's functional equations. Aequat Math, 2015, DOI: 10.1007/s00010-015-0336-4
[30] Székelyhidi L. The stability of d'Alembert-type functional equations. Acta Sci Math, 1982, 44: 313-320
[31] Székelyhidi L. On a theorem of Baker, Lawrence and Zorzitto. Proc Amer Math Soc, 1982, 84: 95-96
[32] Wilson W H. On certain related functional equations. Bull Amer Math Soc, 1920, 26: 300-312
[33] Ulam S M. A Collection of Mathematical Problems. New York: Interscience Publ, 1961; Problems in Modern Mathematics. New York: Wiley, 1964 |