@article{ITA_2001__35_5_419_0,
     author = {Delgado, Manuel},
     title = {Commutative images of rational languages and the abelian kernel of a monoid},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {419--435},
     year = {2001},
     publisher = {EDP Sciences},
     volume = {35},
     number = {5},
     mrnumber = {1908864},
     zbl = {1028.68087},
     language = {en},
     url = {https://www.numdam.org/item/ITA_2001__35_5_419_0/}
}