1. Characterization of inner product spaces;Aczél,1985
2. Derivation and Information Functions (A Tale of Two Surprises and a Half);Aczél,1981
3. Derivations and functional equations basic to characterizations of information measures;Aczél;C.R. Math. Rep. Acad. Sci. Canada,1979
4. Functional equations for the trigonometric functions and related equations;Aczél,1966
5. The general solution of two functional equations by reduction to functions additive in two variables and with the aid of Hamel bases;Aczél;Glas. Nat.-Fiz. Astron.,1965