@article{GDZPPN002550229,
title = {Sur l'\'equation f(x)f(y)f(-x-y) = g(x)g(y)g(-x-y).},
journal = {Aequationes mathematicae},
volume = {20},
year = {1980},
pages = {20-32},
zbl = {0446.39005},
url = {http://dml.mathdoc.fr/item/GDZPPN002550229}
}
Moszner, Zenon. Sur l'équation f(x)f(y)f(-x-y) = g(x)g(y)g(-x-y).. Aequationes mathematicae, Tome 20 (1980) pp. 20-32. http://gdmltest.u-ga.fr/item/GDZPPN002550229/