@article{10_4064_fm_86_3_221_231,
     author = {Saraswathi Subbiah},
     title = {Some finitely generated subsemigroups of {S(X)}},
     journal = {Fundamenta Mathematicae},
     pages = {221--231},
     publisher = {mathdoc},
     volume = {86},
     number = {3},
     year = {1974},
     doi = {10.4064/fm-86-3-221-231},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-86-3-221-231/}
}