@article{GDZPPN001262807,
title = {Affine semigroups and second duals.},
journal = {Semigroup forum},
volume = {46},
year = {1993},
pages = {130-132},
zbl = {0782.22002},
url = {http://dml.mathdoc.fr/item/GDZPPN001262807}
}
Pym, J. Affine semigroups and second duals.. Semigroup forum, Tome 46 (1993) pp. 130-132. http://gdmltest.u-ga.fr/item/GDZPPN001262807/