@article{GDZPPN001262300, title = {A characterization of regular monoids by flatness of left acts.}, journal = {Semigroup forum}, volume = {46}, year = {1993}, pages = {85-89}, zbl = {0766.20024}, url = {http://dml.mathdoc.fr/item/GDZPPN001262300} }
Liu, Z. A characterization of regular monoids by flatness of left acts.. Semigroup forum, Tome 46 (1993) pp. 85-89. http://gdmltest.u-ga.fr/item/GDZPPN001262300/