@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 }, }