@article{GDZPPN00208158X, title = {On a diophantine equation (x2 - 1) (y2 - 1) = (z2 - 1)2.}, journal = {Elemente der Mathematik}, volume = {42}, year = {1987}, pages = {1-3}, zbl = {0699.10027}, url = {http://dml.mathdoc.fr/item/GDZPPN00208158X} }
Hirose, Shoichi. On a diophantine equation (x2 - 1) (y2 - 1) = (z2 - 1)2.. Elemente der Mathematik, Tome 42 (1987) pp. 1-3. http://gdmltest.u-ga.fr/item/GDZPPN00208158X/