@article{GDZPPN002353059, title = {3 as a Ninth Power (mod p).}, journal = {Mathematica Scandinavica}, volume = {34}, year = {1974}, pages = {309-317}, zbl = {0297.10002}, url = {http://dml.mathdoc.fr/item/GDZPPN002353059} }
Williams, Kenneth S. 3 as a Ninth Power (mod p).. Mathematica Scandinavica, Tome 34 (1974) pp. 309-317. http://gdmltest.u-ga.fr/item/GDZPPN002353059/