@article{10_37236_4668,
     author = {Carlos Segovia and Monika Winklmeier},
     title = {On the density of certain languages with \(p^2\) letters},
     journal = {The electronic journal of combinatorics},
     year = {2015},
     volume = {22},
     number = {3},
     doi = {10.37236/4668},
     zbl = {1353.37095},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/4668/}
}