@article{GDZPPN001255371,
title = {Symmetrisations of semigroups.},
journal = {Semigroup forum},
volume = {24},
year = {1982},
pages = {67-76},
zbl = {0505.20042},
url = {http://dml.mathdoc.fr/item/GDZPPN001255371}
}
Osondu, K.E. Symmetrisations of semigroups.. Semigroup forum, Tome 24 (1982) pp. 67-76. http://gdmltest.u-ga.fr/item/GDZPPN001255371/