1. Functional Equations and Inequalities in Several Variables;Czerwik,2002
2. Stability of Functional Equations of Ulam–Hyers–Rassias Type;Czerwik,2003
3. Stability of Functional Equations in Several Variables;Hyers,1998
4. On some inequalities and stability results related to the exponential function;Alsina;J. Inequal. Appl.,1998
5. Hyers stability of the linear differential equation;Obłoza;Rocznik Nauk.-Dydakt. Prace Mat.,1993