@article{SF_1984__28_134667,
     author = {K. Ahre},
     title = {On the closure of {B'} [o,....).},
     journal = {Semigroup forum},
     pages = {377--378},
     publisher = {mathdoc},
     volume = {28},
     year = {1984},
     zbl = {0527.22002},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__28_134667/}
}