@article{00639824,
title = {On the nilpotent rank of partial transformation semigroups.},
journal = {Portugaliae Mathematica. Nova S\'erie},
volume = {51},
year = {1994},
pages = {163-172},
zbl = {0808.20054},
language = {en},
url = {http://dml.mathdoc.fr/item/00639824}
}
Garba, G.U. On the nilpotent rank of partial transformation semigroups.. Portugaliae Mathematica. Nova Série, Tome 51 (1994) pp. 163-172. http://gdmltest.u-ga.fr/item/00639824/