@article{10_21136_CMJ_1991_102438,
     author = {Rach\r{u}nek, Ji\v{r}{\'\i}},
     title = {Convex directed subgroups of right ordered tree groups},
     journal = {Czechoslovak Mathematical Journal},
     pages = {99--103},
     publisher = {mathdoc},
     volume = {41},
     number = {1},
     year = {1991},
     doi = {10.21136/CMJ.1991.102438},
     mrnumber = {1087628},
     zbl = {0803.06020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1991.102438/}
}