@article{SF_1995__50_3_135376,
     author = {N. Kehayopulu and M. Tsingelis},
     title = {On subdirectly irreducible ordered semigroups.},
     journal = {Semigroup forum},
     pages = {161--178},
     publisher = {mathdoc},
     volume = {50},
     number = {3},
     year = {1995},
     zbl = {0823.06010},
     url = {http://geodesic.mathdoc.fr/item/SF_1995__50_3_135376/}
}