@article{GDZPPN002052377, title = {Bewegungsgruppen in mehrdimensionalen R\"aumen.}, journal = {Commentarii mathematici Helvetici}, volume = {9}, year = {1936}, pages = {284-302}, zbl = {0016.39402}, url = {http://dml.mathdoc.fr/item/GDZPPN002052377} }
Burckhardt, Johann Jakob. Bewegungsgruppen in mehrdimensionalen Räumen.. Commentarii mathematici Helvetici, Tome 9 (1936) pp. 284-302. http://gdmltest.u-ga.fr/item/GDZPPN002052377/