@article{MOMA_1977__83_177801,
     author = {Alexander Aigner},
     title = {Der quadratfreie {Kern} der {Eulerschen} {...-Funktion.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {89--92},
     publisher = {mathdoc},
     volume = {83},
     year = {1977},
     zbl = {0353.10003},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1977__83_177801/}
}