@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/