@article{AM2_1971__7_136216,
     author = {T.D. HOWROYD},
     title = {Some {Existence} {Theorems} for {Functional} {Equations} in {Many} {Variables} and the {Characterization} of {Weighted} {Quasi-Arithmetic} {Means}},
     journal = {Aequationes mathematicae},
     pages = {1--15},
     publisher = {mathdoc},
     volume = {7},
     year = {1971},
     zbl = {0236.39009},
     url = {http://geodesic.mathdoc.fr/item/AM2_1971__7_136216/}
}