@article{AM2_1992__43_1_137443,
     author = {Janusz Brzdek},
     title = {Subgroups of the group {Zn} and a generalization of the {Golab-Schinzel} functional equation.},
     journal = {Aequationes mathematicae},
     pages = {59--71},
     publisher = {mathdoc},
     volume = {43},
     number = {1},
     year = {1992},
     zbl = {0757.39003},
     url = {http://geodesic.mathdoc.fr/item/AM2_1992__43_1_137443/}
}