@Article{
  DeMaSpVa16,
  author = { Camillo De Lellis and Andrea Marchese and Emanuele Spadaro and Daniele Valtorta },
  title = { Rectifiability and upper Minkowski bounds for singularities of harmonic $Q$-valued maps },
  journal = { Comm. Math. Helv. },
  year = { 2018 },
  volume = { 93 },
  number = { 4 },
  pages = { 737-779 },
}