A relationship between intersection conditions and porosity conditions for local systems Tomasz Filipczak — 1994 Mathematica Slovaca
On the comparison of the density type topologies generated by sequences and by functions Małgorzata Filipczak; Tomasz Filipczak — 2009 Commentationes Mathematicae In the paper we investigate density type topologies generated by functions f satisfying condition lim inf x 0 + f ( x ) x , which are not generated by any sequence.
Topologies related to (x^α)-porosity Filipczak, Tomasz Acta Universitatis Lodziensis. Folia Mathematica
A note on the system of complements of sets sparse at a point Filipczak, Tomasz Acta Universitatis Lodziensis. Folia Mathematica