@article{SF_1986__33_134788,
     author = {K.D. jr. Magill},
     title = {The monomorphism semigroup of {S(X).}},
     journal = {Semigroup forum},
     pages = {1--14},
     publisher = {mathdoc},
     volume = {33},
     year = {1986},
     zbl = {0581.20064},
     url = {http://geodesic.mathdoc.fr/item/SF_1986__33_134788/}
}