@article{1183503570, author = {van Kampen, E. R.}, title = {Elementary proof of a theorem on Lorentz matrices}, journal = {Bull. Amer. Math. Soc.}, volume = {47}, number = {11}, year = {1941}, pages = { 288-290}, language = {en}, url = {http://dml.mathdoc.fr/item/1183503570} }
van Kampen, E. R. Elementary proof of a theorem on Lorentz matrices. Bull. Amer. Math. Soc., Tome 47 (1941) no. 11, pp. 288-290. http://gdmltest.u-ga.fr/item/1183503570/