@article{GDZPPN002025639,
title = {Some Existence Theorems for Functional Equations in Many Variables and the Characterization of Weighted Quasi-Arithmetic Means},
journal = {Aequationes mathematicae},
volume = {7},
year = {1971},
pages = {1-15},
zbl = {0236.39009},
url = {http://dml.mathdoc.fr/item/GDZPPN002025639}
}
HOWROYD, T.D. Some Existence Theorems for Functional Equations in Many Variables and the Characterization of Weighted Quasi-Arithmetic Means. Aequationes mathematicae, Tome 7 (1971) pp. 1-15. http://gdmltest.u-ga.fr/item/GDZPPN002025639/