@article{SF_1972__4_133876,
     author = {W.D. Munn},
     title = {Embedding semigroups in congruence-free semigroups.},
     journal = {Semigroup forum},
     pages = {46--60},
     publisher = {mathdoc},
     volume = {4},
     year = {1972},
     zbl = {0284.20062},
     url = {http://geodesic.mathdoc.fr/item/SF_1972__4_133876/}
}