@article{10_4064_aa126_2_3,
     author = {P. G. Walsh},
     title = {Sharp bounds for the number of solutions to
 simultaneous {Pellian} equations},
     journal = {Acta Arithmetica},
     pages = {125--137},
     publisher = {mathdoc},
     volume = {126},
     number = {2},
     year = {2007},
     doi = {10.4064/aa126-2-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa126-2-3/}
}