@article{AM2_1977__16_136698,
     author = {R.G. Laha and E. Lukacs},
     title = {On a functional equation which occurs in a characterization problem.},
     journal = {Aequationes mathematicae},
     pages = {259--274},
     publisher = {mathdoc},
     volume = {16},
     year = {1977},
     zbl = {0382.60018},
     url = {http://geodesic.mathdoc.fr/item/AM2_1977__16_136698/}
}