@article{10_37236_2380,
     author = {Padmini Mukkamala and J\'anos Pach and D\"om\"ot\"or P\'alv\"olgyi},
     title = {Lower bounds on the obstacle number of graphs},
     journal = {The electronic journal of combinatorics},
     year = {2012},
     volume = {19},
     number = {2},
     doi = {10.37236/2380},
     zbl = {1243.05176},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/2380/}
}