@article{ITA_1987__21_2_147_0,
     author = {Staiger, Ludwig},
     title = {Sequential mappings of $\omega $-languages},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {147--173},
     publisher = {EDP-Sciences},
     volume = {21},
     number = {2},
     year = {1987},
     mrnumber = {894708},
     zbl = {0634.68070},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1987__21_2_147_0/}
}