@article{AM2_1974__11_136453,
     author = {John A. Baker},
     title = {On the {Functional} {Equation} f(x)g(y) = ...hi(aix + biy).},
     journal = {Aequationes mathematicae},
     pages = {154--162},
     publisher = {mathdoc},
     volume = {11},
     year = {1974},
     url = {http://geodesic.mathdoc.fr/item/AM2_1974__11_136453/}
}