@article{SLC_1988_19_a2,
     author = {Volker Diekert},
     title = {Transitive {Orientations,} {M\"obius} {Functions,} and {Complete} {Semi-Thue} {Systems} for {Free} {Partially} {Commutative} {Monoids}},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {19},
     year = {1988},
     url = {http://geodesic.mathdoc.fr/item/SLC_1988_19_a2/}
}