@article{10_14708_cm_v45i1_5226,
     author = {Jacek Jachymski},
     title = {A covering criterion and its applications to product theorems},
     journal = {Commentationes Mathematicae},
     pages = { 33--41},
     publisher = {mathdoc},
     volume = {45},
     number = {1},
     year = {2005},
     doi = {10.14708/cm.v45i1.5226},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v45i1.5226/}
}