@article{SF_1991__43_3_135091,
     author = {Y.S. Park and J.P. Kim},
     title = {Injective hulls of {S-systems} over a {Clifford} semigroup.},
     journal = {Semigroup forum},
     pages = {19--24},
     publisher = {mathdoc},
     volume = {43},
     number = {3},
     year = {1991},
     zbl = {0727.20045},
     url = {http://geodesic.mathdoc.fr/item/SF_1991__43_3_135091/}
}