@article{SLC_1985_13_a11,
     author = {Helmut Sperber},
     title = {Finite {Automata} {Accepting} {Animals} and {Lower} {Sets}},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {1985},
     volume = {13},
     url = {http://geodesic.mathdoc.fr/item/SLC_1985_13_a11/}
}