@article{CMH_1940__13_138776, author = {F. Fiala}, title = {Le probl\`eme des isop\'erim\`etres sur les surfaces ouvertes \`a courbure positive.}, journal = {Commentarii mathematici Helvetici}, pages = {293--346}, publisher = {mathdoc}, volume = {13}, year = {1940}, zbl = {0025.23003}, url = {http://geodesic.mathdoc.fr/item/CMH_1940__13_138776/} }