@article{NAM_1901_4_1__481_0,
     author = {Collignon, Ed.},
     title = {Probl\`emes sur les normales aux courbes planes},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {481--508},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {4e s{\'e}rie, 1},
     year = {1901},
     language = {fr},
     url = {http://archive.numdam.org/item/NAM_1901_4_1__481_0/}
}