@article{NAM_1858_1_17__435_0,
     author = {Dewulf},
     title = {Note sur le th\'eor\`eme focal d\'emontr\'e p. 179 (question 413)},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {435--436},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {1e s{\'e}rie, 17},
     year = {1858},
     language = {fr},
     url = {http://www.numdam.org/item/NAM_1858_1_17__435_0/}
}