@article{GDZPPN002034913,
title = {On mappings preserving a single Lorentz-Minkowski-distance in Hjelmslev's classical plane.},
journal = {Aequationes mathematicae},
volume = {28},
year = {1985},
pages = {80-87},
zbl = {0575.51009},
url = {http://dml.mathdoc.fr/item/GDZPPN002034913}
}
Benz, Walter. On mappings preserving a single Lorentz-Minkowski-distance in Hjelmslev's classical plane.. Aequationes mathematicae, Tome 28 (1985) pp. 80-87. http://gdmltest.u-ga.fr/item/GDZPPN002034913/