@article{JMPA_1861_2_6__409_0,
     author = {Liouville, J.},
     title = {Sur la forme $x^2+2y^2+4z^2+8t^2$},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {409--416},
     publisher = {Gauthier-Villars},
     volume = {2e s{\'e}rie, 6},
     year = {1861},
     language = {fr},
     url = {http://archive.numdam.org/item/JMPA_1861_2_6__409_0/}
}