@article{ITA_2007__41_2_215_0,
     author = {Honkala, Juha},
     title = {A periodicity property of iterated morphisms},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {215--223},
     publisher = {EDP-Sciences},
     volume = {41},
     number = {2},
     year = {2007},
     doi = {10.1051/ita:2007016},
     mrnumber = {2350645},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/ita:2007016/}
}