@article{JEMS_2011_13_1_a6,
     author = {Angelo Alvino and Vincenzo Ferone and Carlo Nitsch},
     title = {A sharp isoperimetric inequality in the plane},
     journal = {Journal of the European Mathematical Society},
     pages = {185--206},
     publisher = {mathdoc},
     volume = {13},
     number = {1},
     year = {2011},
     doi = {10.4171/jems/248},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/248/}
}