@article{GDZPPN002192829, title = {The diophantine equation x2 + 3 = 7n.}, journal = {Journal f\"ur die reine und angewandte Mathematik}, volume = {281}, year = {1976}, pages = {74-76}, zbl = {0333.10006}, url = {http://dml.mathdoc.fr/item/GDZPPN002192829} }
Brown, Ezra. The diophantine equation x2 + 3 = 7n.. Journal für die reine und angewandte Mathematik, Tome 281 (1976) pp. 74-76. http://gdmltest.u-ga.fr/item/GDZPPN002192829/