@phdthesis{THESE_1921__24__1_0,
     author = {Lebel, J.},
     title = {Sur les surfaces isothermiques et les syst\`emes cycliques},
     series = {Th\`eses de l'entre-deux-guerres},
     number = {24},
     year = {1921},
     language = {fr},
     url = {http://www.numdam.org/item/THESE_1921__24__1_0/}
}