%0 Journal Article %A Thron, Reinhard %A Koppitz, Jörg %T Closure operators and generating sets %J Mathematica slovaca %D 2001 %P 259-268 %V 51 %N 3 %U http://geodesic.mathdoc.fr/item/MASLO_2001_51_3_a1/ %G en %F MASLO_2001_51_3_a1