@article{AM2_1972__8_136275,
     author = {John Lamperti and George O'Brien},
     title = {On a {Functional} {Equation} {Related} to {Iteration.}},
     journal = {Aequationes mathematicae},
     pages = {109--112},
     publisher = {mathdoc},
     volume = {8},
     year = {1972},
     zbl = {0256.39003},
     url = {http://geodesic.mathdoc.fr/item/AM2_1972__8_136275/}
}