@article{ITA_2004__38_1_49_0,
     author = {Silva, Pedro V.},
     title = {Free group languages : rational versus recognizable},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {49--67},
     publisher = {EDP-Sciences},
     volume = {38},
     number = {1},
     year = {2004},
     doi = {10.1051/ita:2004003},
     mrnumber = {2059028},
     zbl = {1082.68071},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/ita:2004003/}
}