@article{AM2_1968__1_135994,
     author = {W. Benz and S. Elliger},
     title = {\"Uber die {Funktionalgleichung} f (1 + x) + f (1 + f (x)) = 1. {(Short} {Communication).}},
     journal = {Aequationes mathematicae},
     pages = {316--317},
     publisher = {mathdoc},
     volume = {1},
     year = {1968},
     zbl = {0165.17201},
     url = {http://geodesic.mathdoc.fr/item/AM2_1968__1_135994/}
}