@article{CM_1976__32_1_41_0,
     author = {Hartfiel, D. J. and Maxson, C. J.},
     title = {Constructing the maximal monoids in the semigroups $\mathcal {N}_n, \mathcal {S}_n$, and $\Omega _n$},
     journal = {Compositio Mathematica},
     pages = {41--52},
     publisher = {Noordhoff International Publishing},
     volume = {32},
     number = {1},
     year = {1976},
     zbl = {0326.20060},
     language = {en},
     url = {http://www.numdam.org/item/CM_1976__32_1_41_0/}
}