@article{CMJ_2008_58_3_a6,
     author = {Sieben, N\'andor},
     title = {Cayley color graphs of inverse semigroups and groupoids},
     journal = {Czechoslovak Mathematical Journal},
     pages = {683--692},
     year = {2008},
     volume = {58},
     number = {3},
     mrnumber = {2455930},
     zbl = {1166.20308},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2008_58_3_a6/}
}