@article{AUPO_1979__18_1_a0,
     author = {Rach\r{u}nek, Ji\v{r}{\'\i}},
     title = {Semi-ordered groups},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {5--20},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {1979},
     mrnumber = {0589842},
     zbl = {0436.06014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_1979__18_1_a0/}
}