@article{10_37236_1077,
     author = {Ghassan Firro and Toufik Mansour},
     title = {Three-letter-pattern avoiding permutations and functional equations},
     journal = {The electronic journal of combinatorics},
     year = {2006},
     volume = {13},
     doi = {10.37236/1077},
     zbl = {1100.05002},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1077/}
}