@article{LJM_2005_18_a6,
     author = {N. Kehayopulu and M. Tsingelis},
     title = {On ordered left groups},
     journal = {Lobachevskii journal of mathematics},
     pages = {131--137},
     publisher = {mathdoc},
     volume = {18},
     year = {2005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/LJM_2005_18_a6/}
}