@article{BSMF_1935__63__121_0,
     author = {Lebesgue, Henri},
     title = {D\'emonstration du th\'eor\`eme fondamental de la th\'eorie projective des coniques faite \`a l'aide des droites focales de {M.} {P.} {Robert}},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {121--154},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {63},
     year = {1935},
     doi = {10.24033/bsmf.1229},
     zbl = {0012.03103},
     language = {fr},
     url = {http://www.numdam.org/articles/10.24033/bsmf.1229/}
}