@article{JMPA_1846_1_11__331_0,
     author = {Lebesgue},
     title = {Sur les arcs \`a diff\'erence rectifiable et les zones \`a diff\'erence planifiable},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {331--335},
     publisher = {Gauthier-Villars},
     volume = {1e s{\'e}rie, 11},
     year = {1846},
     language = {fr},
     url = {http://www.numdam.org/item/JMPA_1846_1_11__331_0/}
}