Realizations of topologies and closure operators by set systems and by neighbourhoods Horst Herrlich (1989) Archivum Mathematicum
Reflective Mac Neille completions of fibre-small categories need not be fibre-small Horst Herrlich (1978) Commentationes Mathematicae Universitatis Carolinae
Representability of concrete categories by non-constant morphisms Jiří Rosický, Věra Trnková (1989) Archivum Mathematicum
Representations in varieties of regular involution bands Václav Koubek (1990) Commentationes Mathematicae Universitatis Carolinae