@article{ITA_1997__31_4_355_0,
     author = {Carton, O.},
     title = {A hierarchy of cyclic languages},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {355--369},
     publisher = {EDP-Sciences},
     volume = {31},
     number = {4},
     year = {1997},
     mrnumber = {1605786},
     zbl = {0892.68056},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1997__31_4_355_0/}
}