@article{2967, author = {Hardy, J.T.}, title = {Sums of three squares in certain Cayley rings}, journal = {Portugaliae mathematica}, volume = {40}, year = {1981}, pages = {313-323}, zbl = {0576.10016}, mrnumber = {0819897}, language = {en}, url = {http://dml.mathdoc.fr/item/2967} }
Hardy, J.T. Sums of three squares in certain Cayley rings. Portugaliae mathematica, Tome 40 (1981) pp. 313-323. http://gdmltest.u-ga.fr/item/2967/