@Article{ 
  NovRuf14,
  author = { Novaga, Matteo and Ruffini, Berardo },
  title = { Brunn-Minkowski inequality for the 1-Riesz capacity and level set
  convexity for the 1/2-Laplacian },
  journal = { J. Convex Anal. },
  year = { 2015 },
  volume = { 22 },
  number = { 4 },
  pages = { 1125-1134 },
  URL = { http://cvgmt.sns.it/paper/2335/ },
  note = { cvgmt preprint}
}