Remarks on I -density and I -approximately continuous functions Poreda, W.; Elzbieta Wagner-Bojakowska; Władysław Wilczyński — 1985 Commentationes Mathematicae Universitatis Carolinae
A category analogue of the density topology W. Poreda; E. Wagner-Bojakowska; Władysław Wilczyński — 1985 Fundamenta Mathematicae