@article{SF_1986__34_134837,
     author = {W. Forys},
     title = {Fixed point languages of rational transductions.},
     journal = {Semigroup forum},
     pages = {177--184},
     publisher = {mathdoc},
     volume = {34},
     year = {1986},
     zbl = {0618.68065},
     url = {http://geodesic.mathdoc.fr/item/SF_1986__34_134837/}
}