@article{MZ_1982__180_173200,
     author = {Frank R\"ohl},
     title = {On the {Isomorphism} {Problem} for {Integral} {Group-Rings} of {Circle-Groups.}},
     journal = {Mathematische Zeitschrift},
     pages = {419--422},
     publisher = {mathdoc},
     volume = {180},
     year = {1982},
     zbl = {0484.20003},
     url = {http://geodesic.mathdoc.fr/item/MZ_1982__180_173200/}
}