@article{NAM_1899_3_18__512_0,
     author = {Lefebvre},
     title = {\'Etude d'un syst\`eme de deux miroirs sph\'eriques},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {512--529},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {3e s{\'e}rie, 18},
     year = {1899},
     language = {fr},
     url = {http://archive.numdam.org/item/NAM_1899_3_18__512_0/}
}