@article{NAM_1908_4_8__145_0,
     author = {Charbonnier, P.},
     title = {Sur la th\'eorie des perturbations du pendule},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {145--162},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {4e s{\'e}rie, 8},
     year = {1908},
     language = {fr},
     url = {http://www.numdam.org/item/NAM_1908_4_8__145_0/}
}