@article{GDZPPN00126396X,
title = {Monoids over which all regular left acts are flat.},
journal = {Semigroup forum},
volume = {51},
year = {1995},
pages = {135-140},
zbl = {0827.20078},
url = {http://dml.mathdoc.fr/item/GDZPPN00126396X}
}
Liu, Z. Monoids over which all regular left acts are flat.. Semigroup forum, Tome 51 (1995) pp. 135-140. http://gdmltest.u-ga.fr/item/GDZPPN00126396X/