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

A characterization of continuous associative operations whose graphs are ruled surfaces. C. Alsina, A. Sklar (1987) Aequationes 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 characterization of midconvex set-valued functions Kazimierz Nikodem (1989) Acta Universitatis Carolinae. Mathematica et Physica

A characterization of some classes of functions F of the form F(x, y) = g(...f(x) + ßf(y) + ...) or F(x, y) = ...(h(x) + k(y)). Luigi Paganoni, Daniela Rusconi (1983) Aequationes mathematicae

A characterization of $\lambda $-convex functions. Adamek, Mirosław (2004) JIPAM. Journal of Inequalities in Pure & Applied Mathematics [electronic only]

A class of hypertranscendental functions. J.H. Loxton, A.J. van der Poorten (1977) Aequationes mathematicae

A class of hypertranscendental functions. (Short Communication). J.H. Loxton, A.J. van der Poorten (1977) Aequationes mathematicae

A class of nowhere continuous solutions of Baxter's equation. Walter Benz (1986) Aequationes mathematicae

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

A comparative study of functional equations characterising sine and cosine. H.L. Vasudeva, J.C. Parnami (1986) Aequationes mathematicae