@ARTICLE{JouBacAbsSep2010, author = "M. Journée and F. Bach and P.-A. Absil and R. Sepulchre", title= "Low-Rank Optimization on the Cone of Positive Semidefinite Matrices", journal = "SIAM J. Optim", fjournal = "SIAM Journal on Optimization", year = 2010, volume = 20, number = 5, pages = "2327--2351", }