Narrow spaces, products of topological spaces and supertiny sequences of A. Szymański
New approach for closure spaces by relations.
Non-normality and relative normality of Niemytzki plane
Non-separating subcontinua of planar continua
We revisit an old question of Knaster by demonstrating that each non-degenerate plane hereditarily unicoherent continuum X contains a proper, non-degenerate subcontinuum which does not separate X.
Numerical invariants of 0-dimensional spaces and their Cartesian multiplication.