S.  Petra, Popa, C., and Schnörr, C., ?Enhancing Sparsity by Constraining Strategies: Constrained SIRT versus Spectral Projected Gradient Methods?, in Proc. 7th Workshop on Modelling of Environmental and Life Sciences Problems (WMM 08), Constanta, Romania, 2008.

S.  Petra, Popa, C., and Schnörr, C., ?Enhancing Sparsity by Constraining Strategies: Constrained SIRT versus Spectral Projected Gradient Methods?, in Proc. 7th Workshop on Modelling of Environmental and Life Sciences Problems (WMM 08), Bucharest, Romania, 2008.