@article{SF_1984__29_134699,
     author = {W. Forys},
     title = {A fixed point characterization of cofinite languages.},
     journal = {Semigroup forum},
     pages = {378--380},
     publisher = {mathdoc},
     volume = {29},
     year = {1984},
     zbl = {0549.20052},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__29_134699/}
}