@article{NAM_1853_1_12__57_0,
     author = {Laguerre-Verly, Edmond},
     title = {Note sur la th\'eorie des foyers},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {57--66},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {1e s{\'e}rie, 12},
     year = {1853},
     language = {fr},
     url = {http://www.numdam.org/item/NAM_1853_1_12__57_0/}
}