@article{10_4153_CMB_2009_048_x,
     author = {Pach, J\'anos and Tardos, G\'abor and T\'oth, G\'eza},
     title = {Indecomposable {Coverings}},
     journal = {Canadian mathematical bulletin},
     pages = {451--463},
     year = {2009},
     volume = {52},
     number = {3},
     doi = {10.4153/CMB-2009-048-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-2009-048-x/}
}