@article{MS2_1967__21_166015,
     author = {W. Ljunggren},
     title = {On the {Diophantine} {Equation} {Ax4} {-By2} = {C} {(C} = 1, 4).},
     journal = {Mathematica Scandinavica},
     pages = {149--158},
     publisher = {mathdoc},
     volume = {21},
     year = {1967},
     zbl = {0169.37302},
     url = {http://geodesic.mathdoc.fr/item/MS2_1967__21_166015/}
}