@article{SF_1984__29_134696,
     author = {W. Williams and Carl Eberhart},
     title = {Elementary orthodox semigroups.},
     journal = {Semigroup forum},
     pages = {351--364},
     publisher = {mathdoc},
     volume = {29},
     year = {1984},
     zbl = {0547.20053},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__29_134696/}
}