@article{BAG_1987__24_138361,
     author = {Tatsuhiko Saito},
     title = {Semigroup theoretical approach to normal ideals},
     journal = {Beitr\"age zur Algebra und Geometrie},
     pages = {99--110},
     publisher = {mathdoc},
     volume = {24},
     year = {1987},
     zbl = {0613.20040},
     url = {http://geodesic.mathdoc.fr/item/BAG_1987__24_138361/}
}