@workingPaper{AltMehlhornWagenerWelzl_1987,
title={Congruence, similarity and symmetries of geometric objects},
author={Alt, Helmut and Mehlhorn, Kurt and Wagener, Hubert and Welzl, Emo},
doi={http://dx.doi.org/10.22028/D291-26119},
year={1987}
}