@article{SLC_1987_18_a16,
     author = {Werner Kuich},
     title = {Semirings, {Automata} and {Combinatorial} {Applications}},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {1987},
     volume = {18},
     url = {http://geodesic.mathdoc.fr/item/SLC_1987_18_a16/}
}