@techreport {petra09b, title = {Accelerating Constrained SIRT with Applications in Tomographic Particle Image Reconstruction}, year = {2009}, institution = {IWR, University of Heidelberg}, url = {http://www.ub.uni-heidelberg.de/archiv/9477}, author = {Stefania Petra and Popa, C. and Christoph Schn{\"o}rr} }