@article{GDZPPN001249290, title = {The dual ordinal of a bisimple inverse semigroup.}, journal = {Semigroup forum}, volume = {7}, year = {1974}, pages = {295-297}, zbl = {0267.20055}, url = {http://dml.mathdoc.fr/item/GDZPPN001249290} }
White, G.L. The dual ordinal of a bisimple inverse semigroup.. Semigroup forum, Tome 7 (1974) pp. 295-297. http://gdmltest.u-ga.fr/item/GDZPPN001249290/