@article{MOMA_1981__91_178006,
     author = {Ernst Heppner},
     title = {\"Uber {Mittelwerte} multiplikativver zahlentheoretischer {Funktionen} mehrerer {Variablen.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {1--10},
     publisher = {mathdoc},
     volume = {91},
     year = {1981},
     zbl = {0448.10039},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1981__91_178006/}
}