@article{AM2_1993__45_2-3_137509,
     author = {Franz Halter-Koch and Ludwig Reich},
     title = {On products of additive functions.},
     journal = {Aequationes mathematicae},
     pages = {83--88},
     publisher = {mathdoc},
     volume = {45},
     number = {2-3},
     year = {1993},
     zbl = {0773.39006},
     url = {http://geodesic.mathdoc.fr/item/AM2_1993__45_2-3_137509/}
}