Fouvry, É., &; Klüners, J. (2010). On the negative Pell equation. Annals of Mathematics, 172(3), 2035–2104.https://doi.org/10.4007/annals.2010.172.2035 
LibreCat: /record/34886
DOI: 10.4007/annals.2010.172.2035