@article{SF_1994__49_2_135342,
     author = {N. Hindman and A.T. Lisan},
     title = {Points very close to the smallest ideal of {{\ss}S.}},
     journal = {Semigroup forum},
     pages = {137--142},
     publisher = {mathdoc},
     volume = {49},
     number = {2},
     year = {1994},
     zbl = {0826.22005},
     url = {http://geodesic.mathdoc.fr/item/SF_1994__49_2_135342/}
}