@article{NAM_1909_4_9__518_0,
     author = {Egan, M.-F.},
     title = {Note sur les quadriques circonscrites \`a deux sph\`eres},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {518--523},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {4e s{\'e}rie, 9},
     year = {1909},
     language = {fr},
     url = {http://www.numdam.org/item/NAM_1909_4_9__518_0/}
}