Peter Gritzmann Barbara Langfeld On the index of Siegel grids and its application to the tomography of quasicrystals. 1894-1909 2008 29 Eur. J. Comb. 8 http://dx.doi.org/10.1016/j.ejc.2008.01.017 db/journals/ejc/ejc29.html#GritzmannL08