@article{CMJ_1999__49_4_a6,
     author = {Giraudet, Mich\`ele and Rach\r{u}nek, Ji\v{r}{\'\i}},
     title = {Varieties of half lattice-ordered groups of monotonic permutations of chains},
     journal = {Czechoslovak Mathematical Journal},
     pages = {743--766},
     publisher = {mathdoc},
     volume = {49},
     number = {4},
     year = {1999},
     mrnumber = {1746701},
     zbl = {1054.06006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_1999__49_4_a6/}
}