On the Diophantine Equation $Ax^4-By^2=C$, ($C=1,4$).

Ljunggren, W. (1967). On the Diophantine Equation $Ax^4-By^2=C$, ($C=1,4$). MATHEMATICA SCANDINAVICA, 21, 149–158. https://doi.org/10.7146/math.scand.a-10855