@article{GDZPPN001254804, title = {Which semilattice indecomposables are groups?}, journal = {Semigroup forum}, volume = {23}, year = {1981}, pages = {243-246}, zbl = {0466.20039}, url = {http://dml.mathdoc.fr/item/GDZPPN001254804} }
Nordahl, T.E.; Scheiblich, H.E. Which semilattice indecomposables are groups?. Semigroup forum, Tome 23 (1981) pp. 243-246. http://gdmltest.u-ga.fr/item/GDZPPN001254804/