@article{1077473261,
author = {Williams, Christine S. and Pall, G.},
title = {The thirty-nine systems of quaternions with a positive
norm-form and satisfactory factorability},
journal = {Duke Math. J.},
volume = {12},
number = {1},
year = {1945},
pages = { 527-539},
language = {en},
url = {http://dml.mathdoc.fr/item/1077473261}
}
Williams, Christine S.; Pall, G. The thirty-nine systems of quaternions with a positive
norm-form and satisfactory factorability. Duke Math. J., Tome 12 (1945) no. 1, pp. 527-539. http://gdmltest.u-ga.fr/item/1077473261/