E. Lopez-Rubio, K. Thurnhofer-Hemsi, O. D. de Cozar-Macias, E. B. Blazquez-Parra, J. Muñoz-Perez, and I. Ladron de Guevara-Lopez. Robust Fitting of Ellipsoids by Separating Interior and Exterior Points During Optimization. Journal of Mathematical Imaging and Vision. ISSN: 0924-9907.
http://dx.doi.org/10.1007/s10851-016-0700-6