@article{AMI_2010_37_a6,
     author = {Attila Egri-Nagy and Chrystopher L. Nehaniv},
     title = {On the skeleton of a finite transformation semigroup},
     journal = {Annales mathematicae et informaticae},
     pages = {77--84},
     publisher = {mathdoc},
     volume = {37},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AMI_2010_37_a6/}
}