@article{JRAM_1878__85_148375,
     author = {Ch. Hermite},
     title = {Sur le pendule. {(Extrait} d'une lettre adress\'ee \`a {M.} {Gyld\'en,} de {Stockholm,} par {M.} {Ch.} {Hermite).}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {246--249},
     publisher = {mathdoc},
     volume = {85},
     year = {1878},
     zbl = {10.0622.05},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1878__85_148375/}
}