@article{AM2_1989__37_2-3_137300,
     author = {S.L. Segal},
     title = {Iterative characterizations of powers and exponentials.},
     journal = {Aequationes mathematicae},
     pages = {201--218},
     publisher = {mathdoc},
     volume = {37},
     number = {2-3},
     year = {1989},
     zbl = {0669.30016},
     url = {http://geodesic.mathdoc.fr/item/AM2_1989__37_2-3_137300/}
}