@article{JMPA_1936_9_15__25_0,
     author = {Lebel, J.},
     title = {Enveloppes de cercles ou de sph\`eres. {Surfaces} applicables},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {25--41},
     publisher = {Gauthier-Villars},
     volume = {9e s{\'e}rie, 15},
     year = {1936},
     zbl = {0013.27903},
     language = {fr},
     url = {http://archive.numdam.org/item/JMPA_1936_9_15__25_0/}
}