@article{NAM_1842_1_1__417_1,
     author = {Vachette},
     title = {Note sur les foyers},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {417--420},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {1e s{\'e}rie, 1},
     year = {1842},
     language = {fr},
     url = {http://archive.numdam.org/item/NAM_1842_1_1__417_1/}
}