@article{GDZPPN001255169, title = {The injective hull of S-sets, S a semilattice of groups.}, journal = {Semigroup forum}, volume = {23}, year = {1981}, pages = {241-246}, zbl = {0479.20035}, url = {http://dml.mathdoc.fr/item/GDZPPN001255169} }
Burgess, W.D. The injective hull of S-sets, S a semilattice of groups.. Semigroup forum, Tome 23 (1981) pp. 241-246. http://gdmltest.u-ga.fr/item/GDZPPN001255169/