Beckman, F. S.; Quarles, D. A., Jr. (1953), “On isometries of Euclidean spaces”, 《Proceedings of the American Mathematical Society》 (영어) 4: 810–815, doi:10.2307/2032415, MR0058193
Townsend, Carl G. (1970), “Congruence-preserving mappings”, 《Mathematics Magazine》 (영어) 43: 37–38, doi:10.2307/2688111, MR0256252
Bishop, Richard L. (1973), “Characterizing motions by unit distance invariance”, 《Mathematics Magazine》 (영어) 46: 148–151, doi:10.2307/2687969, MR0319026
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dx.doi.org
Beckman, F. S.; Quarles, D. A., Jr. (1953), “On isometries of Euclidean spaces”, 《Proceedings of the American Mathematical Society》 (영어) 4: 810–815, doi:10.2307/2032415, MR0058193
Townsend, Carl G. (1970), “Congruence-preserving mappings”, 《Mathematics Magazine》 (영어) 43: 37–38, doi:10.2307/2688111, MR0256252
Bishop, Richard L. (1973), “Characterizing motions by unit distance invariance”, 《Mathematics Magazine》 (영어) 46: 148–151, doi:10.2307/2687969, MR0319026