@article{10_4007_annals_2010_172_2035,
     author = {\'Etienne Fouvry and J\"urgen Kl\"uners},
     title = {On the negative {Pell} equation},
     journal = {Annals of mathematics},
     pages = {2035--2104},
     publisher = {mathdoc},
     volume = {172},
     number = {3},
     year = {2010},
     doi = {10.4007/annals.2010.172.2035},
     mrnumber = {2726105},
     zbl = {05850192},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4007/annals.2010.172.2035/}
}