@article{AM2_1995__50_1-2_137624,
     author = {Gian Luigi Forti},
     title = {Hyers-Ulam stability of functional equations in several variables.},
     journal = {Aequationes mathematicae},
     pages = {143--190},
     publisher = {mathdoc},
     volume = {50},
     number = {1-2},
     year = {1995},
     zbl = {0836.39007},
     url = {http://geodesic.mathdoc.fr/item/AM2_1995__50_1-2_137624/}
}