Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{MASLO_1979__29_1_a3, author = {Rach\r{u}nek, Ji\v{r}{\'\i}}, title = {$Z$-subgroups of ordered groups}, journal = {Mathematica slovaca}, pages = {39--41}, publisher = {mathdoc}, volume = {29}, number = {1}, year = {1979}, mrnumber = {561774}, zbl = {0401.06010}, language = {en}, url = {http://geodesic.mathdoc.fr/item/MASLO_1979__29_1_a3/} }
Rachůnek, Jiří. $Z$-subgroups of ordered groups. Mathematica slovaca, Tome 29 (1979) no. 1, pp. 39-41. http://geodesic.mathdoc.fr/item/MASLO_1979__29_1_a3/