@article{10_1017_S0017089500030482,
     author = {Garba, G. U.},
     title = {On the nilpotent ranks of certain semigroups of transformations},
     journal = {Glasgow mathematical journal},
     pages = {1--9},
     year = {1994},
     volume = {36},
     number = {1},
     doi = {10.1017/S0017089500030482},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500030482/}
}