@article{AM2_1981__22_136849,
     author = {L. Sweet},
     title = {On the generalized cube and octahedron functional equations.},
     journal = {Aequationes mathematicae},
     pages = {29--38},
     year = {1981},
     volume = {22},
     zbl = {0475.39016},
     url = {http://geodesic.mathdoc.fr/item/AM2_1981__22_136849/}
}