@article{BMMS_2011_34_1_a6,
     author = {V{\'\i}tor H. Fernandes and Gracinda M. S. Gomes and Manuel M. Jesus},
     title = {The {Cardinal} and the {Idempotent} {Number} of {Various} {Monoids} of {Transformations} on a {Finite} {Chain}},
     journal = {Bulletin of the Malaysian Mathematical Society},
     year = {2011},
     volume = {34},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/BMMS_2011_34_1_a6/}
}