@article{NAM_1919_4_19__81_0,
     author = {d'Ocagne, Maurice},
     title = {Sur l'h\'elico{\"\i}de gauche},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {81--89},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {4e s{\'e}rie, 19},
     year = {1919},
     language = {fr},
     url = {http://archive.numdam.org/item/NAM_1919_4_19__81_0/}
}