@article{MASLO_1994_44_4_a4,
     author = {Mitsch, Heinz},
     title = {Semigroups and their natural order},
     journal = {Mathematica slovaca},
     pages = {445--462},
     year = {1994},
     volume = {44},
     number = {4},
     mrnumber = {1301953},
     zbl = {0816.20057},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1994_44_4_a4/}
}