@article{SF_1980__19_134396,
     author = {O. Steinfeld},
     title = {Quasi-ideals in rings and semigroups},
     journal = {Semigroup forum},
     pages = {371--372},
     publisher = {mathdoc},
     volume = {19},
     year = {1980},
     url = {http://geodesic.mathdoc.fr/item/SF_1980__19_134396/}
}