@article{10_37236_1833,
     author = {Reid W. Barton},
     title = {Packing densities of patterns},
     journal = {The electronic journal of combinatorics},
     year = {2004},
     volume = {11},
     number = {1},
     doi = {10.37236/1833},
     zbl = {1061.05007},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1833/}
}