@article{RSMUP_1997__98__213_0,
     author = {Gutierrez, Carlos and S\'anchez-Bringas, Federico},
     title = {On a {Carath\'eodory's} conjecture on umbilics : representing ovaloids},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {213--219},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {98},
     year = {1997},
     mrnumber = {1492978},
     zbl = {0897.53003},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_1997__98__213_0/}
}