@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/