@article{GDZPPN002477378, title = {On the Diophantine Equation x2 + D = 4yq.}, journal = {Monatshefte f\"ur Mathematik}, volume = {75}, year = {1971}, pages = {136-143}, zbl = {0216.04003}, url = {http://dml.mathdoc.fr/item/GDZPPN002477378} }
Ljunggren, W. On the Diophantine Equation x2 + D = 4yq.. Monatshefte für Mathematik, Tome 75 (1971) pp. 136-143. http://gdmltest.u-ga.fr/item/GDZPPN002477378/