@article{SF_1985__32_134768,
     author = {J.D. Lawson and M. Mislove},
     title = {Semilattices which must contain a copy of  2 {N.}},
     journal = {Semigroup forum},
     pages = {71--78},
     publisher = {mathdoc},
     volume = {32},
     year = {1985},
     zbl = {0564.06003},
     url = {http://geodesic.mathdoc.fr/item/SF_1985__32_134768/}
}