On an Equivalence Relation for Free Mappings Embeddeable in a Flow. - Zbigniew Lesniak (Int. J. Bifurc. Chaos, 2003)

On Ulam Stability of Functional Equations in 2-Normed Spaces - A Survey. - Anna Bahyrycz; Janusz Brzdek; El-Sayed El-Hady; Zbigniew Lesniak (Symmetry, 2021)

On the Stability of a Generalized Fréchet Functional Equation with Respect to Hyperplanes in the Parameter Space. - Janusz Brzdek; Zbigniew Lesniak; Renata Malejki (Symmetry, 2021)

Ulam Stability of a General Linear Functional Equation in Modular Spaces. - Issam Aboutaib; Chaimaa Benzarouala; Janusz Brzdek; Zbigniew Lesniak; Lahbib Oubbi (Symmetry, 2022)