@article{SF_1972__4_133886,
     author = {A. Yiu-{\textyen}a Lau},
     title = {Small semilattices.},
     journal = {Semigroup forum},
     pages = {150--155},
     year = {1972},
     volume = {4},
     url = {http://geodesic.mathdoc.fr/item/SF_1972__4_133886/}
}