Some remarks about homeomorphisms preserving (f)-porosity Niewiarowski, Jerzy Acta Universitatis Lodziensis. Folia Mathematica
Porosity preserving homeomorphisms Niewiarowski, Jerzy Acta Universitatis Lodziensis. Folia Mathematica
Convergence of sequences of real functions with respect to small systems Jerzy Niewiarowski — 1988 Mathematica Slovaca