@article{FORUM_1993__5_3_141704,
     author = {Friedrich Wehrung},
     title = {Metric properties of positively ordered monoids.},
     journal = {Forum mathematicum},
     pages = {183--202},
     publisher = {mathdoc},
     volume = {5},
     number = {3},
     year = {1993},
     zbl = {0769.06008},
     url = {http://geodesic.mathdoc.fr/item/FORUM_1993__5_3_141704/}
}