@article{GDZPPN002179946,
title = {4-dimensional Orthogonal Groups over Algebraic Number Fields.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {211},
year = {1962},
pages = {176-178},
zbl = {0118.03903},
url = {http://dml.mathdoc.fr/item/GDZPPN002179946}
}
Pollak, Barth. 4-dimensional Orthogonal Groups over Algebraic Number Fields.. Journal für die reine und angewandte Mathematik, Tome 211 (1962) pp. 176-178. http://gdmltest.u-ga.fr/item/GDZPPN002179946/