@article{MOMA_1972__76_177603,
     author = {Richard Warlimont},
     title = {\"Uber quadratfreie {Zahlen} in arithmetischen {Progressionen.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {272--275},
     publisher = {mathdoc},
     volume = {76},
     year = {1972},
     zbl = {0243.10036},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1972__76_177603/}
}