@article{NAM_1875_2_14__171_1,
     author = {Joffroy, Joseph},
     title = {D\'emonstration g\'eom\'etrique de l{\textquoteright}in\'egalit\'e
$a-\sin a < \frac{a^3}{4}$},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {171--172},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {2e s{\'e}rie, 14},
     year = {1875},
     language = {fr},
     url = {http://www.numdam.org/item/NAM_1875_2_14__171_1/}
}