@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},
     year = {1940},
     volume = {13},
     zbl = {0025.23003},
     url = {http://geodesic.mathdoc.fr/item/CMH_1940__13_138776/}
}