@article{AM2_1986__30_137122,
     author = {Peter Volkmann and Lutz Volkmann},
     title = {\"Uber die {Charakterisierung} der {Funktion} f(x) = x durch {Funktionalgleichungen,} {II.}},
     journal = {Aequationes mathematicae},
     pages = {142--150},
     publisher = {mathdoc},
     volume = {30},
     year = {1986},
     zbl = {0591.39001},
     url = {http://geodesic.mathdoc.fr/item/AM2_1986__30_137122/}
}