@article{ASENS_1961_3_78_4_305_0,
     author = {Borel, F.},
     title = {Sur certaines propri\'et\'es invariantes par d\'eformation des congruences de droites, de cercles ou de sph\`eres},
     journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure},
     pages = {305--412},
     publisher = {Elsevier},
     volume = {3e s{\'e}rie, 78},
     number = {4},
     year = {1961},
     doi = {10.24033/asens.1104},
     mrnumber = {25 #497},
     zbl = {0105.15201},
     language = {fr},
     url = {http://www.numdam.org/articles/10.24033/asens.1104/}
}