@article{JRAM_1990__405_153214,
     author = {Patrick Morton},
     title = {On the non-existence of abelian conditions governing solvability of the  - 1 {Pell} equation.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {147--155},
     publisher = {mathdoc},
     volume = {405},
     year = {1990},
     zbl = {0689.12006},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1990__405_153214/}
}