@article{MOMA_1951__55_176874,
     author = {L.J. Mordell},
     title = {On the {Equation} ax2 + by2 - cz2 = 0.},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {323--327},
     publisher = {mathdoc},
     volume = {55},
     year = {1951},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1951__55_176874/}
}