@article{AM2_1981__22_136863,
     author = {K. Niino},
     title = {On a functional equation. {(Short} {Communication).}},
     journal = {Aequationes mathematicae},
     pages = {113--114},
     publisher = {mathdoc},
     volume = {22},
     year = {1981},
     url = {http://geodesic.mathdoc.fr/item/AM2_1981__22_136863/}
}