@article{GDZPPN002402203, title = {Multiplicative Twins and Primitive Roots.}, journal = {Mathematische Zeitschrift}, volume = {105}, year = {1968}, pages = {49-58}, zbl = {0165.05704}, url = {http://dml.mathdoc.fr/item/GDZPPN002402203} }
Bernstein, Leon. Multiplicative Twins and Primitive Roots.. Mathematische Zeitschrift, Tome 105 (1968) pp. 49-58. http://gdmltest.u-ga.fr/item/GDZPPN002402203/