@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/