@article{AM2_1971__6_136195,
     author = {J. PFANZAGL and G. LAUBE},
     title = {A {Remark} on the {Functional} {Equation} ... (xi) = ....},
     journal = {Aequationes mathematicae},
     pages = {241--242},
     publisher = {mathdoc},
     volume = {6},
     year = {1971},
     zbl = {0222.39005},
     url = {http://geodesic.mathdoc.fr/item/AM2_1971__6_136195/}
}