A canonical form for a system of quadratic functional equations J. A. Lester (1976) Colloquium Mathematicae

A characterization of convolution and related operations. Claudi Alsina (1985) Aequationes mathematicae

A characterization of damped and undamped harmonic oscillations by a superposition property II. Schöpf, Peter, Schwaiger, Jens (2005) Mathematica Pannonica

A characterization of derivations by functional equations. Halter-Koch, Franz (2000) Mathematica Pannonica

A characterization of generalized inner product spaces (?-orthogonally additive mappings, III). Gy. Szabó (1991) Aequationes mathematicae

A class of symmetric biadditive functionals. P. Fischer, J.P. Mokansi (1981) Aequationes mathematicae

A contribution to a theorem of Ulam and Mazur. Walter Benz, Hubert Berens (1987) Aequationes mathematicae

A Cosine Functional Equation with Restricted Argument. (Short Communication). L.B. Etigson (1974) Aequationes mathematicae

A family of symmetric biadditive nonbilinear functions. Konrad D. Heuvers (1985) Aequationes mathematicae

A few remarks on automorphic functions. Keckic, Jovan D. (1981) Publications de l'Institut Mathématique. Nouvelle Série

A fixed point approach to the fuzzy stability of an additive-quadratic-cubic functional equation. Park, Choonkil (2009) Fixed Point Theory and Applications [electronic only]

A fixed point approach to the stability of a functional equation of the spiral of Theodorus. Jung, Soon-Mo, Rassias, John Michael (2008) Fixed Point Theory and Applications [electronic only]

A fixed point approach to the stability of a general mixed AQCQ-functional equation in non-Archimedean normed spaces. Xu, Tian Zhou, Rassias, John Michael, Xu, Wan Xin (2010) Discrete Dynamics in Nature and Society

A fixed point approach to the stability of a generalized Cauchy functional equation. Najati, Abbas, Rahimi, Asghar (2008) Banach Journal of Mathematical Analysis [electronic only]

A fixed point approach to the stability of a quadratic functional equation in ${C}^{*}$-algebras. Moghimi, Mohammad B., Najati, Abbas, Park, Choonkil (2009) Advances in Difference Equations [electronic only]