@article{AM2_1989__38_1_137326,
     author = {S\'andor Szab\'o},
     title = {On a problem of {A.D.} {Sands.}},
     journal = {Aequationes mathematicae},
     pages = {186--191},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1989},
     zbl = {0685.20023},
     url = {http://geodesic.mathdoc.fr/item/AM2_1989__38_1_137326/}
}