Andreas Alpers Erik Knudsen Henning Friis Poulsen Gabor T. Herman Resolving Ambiguities in Reconstructed Grain Maps using Discrete Tomography. 419-437 2005 20 Electronic Notes in Discrete Mathematics http://dx.doi.org/10.1016/j.endm.2005.05.076 db/journals/endm/endm20.html#AlpersKPH05