@article{AM2_1973__9_136381,
     author = {WALTER BENZ},
     title = {On the {Functional} {Equation} of {Distance} {Preserving} {Mappings} over {Rings} {(\"Uber} die {Funktionalgleichung} der {L\"angentreue} im {Ringbereich)} {(Short} {Communication)}},
     journal = {Aequationes mathematicae},
     pages = {316--317},
     publisher = {mathdoc},
     volume = {9},
     year = {1973},
     url = {http://geodesic.mathdoc.fr/item/AM2_1973__9_136381/}
}