@article{GDZPPN001264028,
title = {Direct products of cyclic semigroups and unions of groups.},
journal = {Semigroup forum},
volume = {51},
year = {1995},
pages = {223-232},
zbl = {0828.20048},
url = {http://dml.mathdoc.fr/item/GDZPPN001264028}
}
Jackson, D.C. Direct products of cyclic semigroups and unions of groups.. Semigroup forum, Tome 51 (1995) pp. 223-232. http://gdmltest.u-ga.fr/item/GDZPPN001264028/