@article{SF_1984__29_134695,
     author = {D.W. Hardy and M.C. Thornton},
     title = {The intersection of the maximal regular subsemigroups of the semigroup of binary relations.},
     journal = {Semigroup forum},
     pages = {343--350},
     publisher = {mathdoc},
     volume = {29},
     year = {1984},
     zbl = {0536.20042},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__29_134695/}
}