@ARTICLE{Journee2010,
  author = {Journee, M. and Bach, F. and Absil, P.-A. and Sepulchre, R.},
  title = {{Low-Rank Optimization on the Cone of Positive Semidefinite Matrices}},
  journal = {SIAM Journal on Optimization},
  year = {2010},
  volume = {20},
  pages = {2327},
}