@article{NAM_1857_1_16__319_1,
     author = {Lebesgue},
     title = {Sur l'aire du triangle sph\'erique},
     journal = {Nouvelles annales de math\'ematiques : journal des candidats aux \'ecoles polytechnique et normale},
     pages = {319--321},
     publisher = {Carilian-Goeury et Vor Dalmont},
     volume = {1e s{\'e}rie, 16},
     year = {1857},
     language = {fr},
     url = {http://www.numdam.org/item/NAM_1857_1_16__319_1/}
}