@article{SF_1984__29_134690,
     author = {J. Clarke},
     title = {Rees quotients of {N-semigroups.}},
     journal = {Semigroup forum},
     pages = {259--270},
     publisher = {mathdoc},
     volume = {29},
     year = {1984},
     zbl = {0553.20039},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__29_134690/}
}