H. J. Herrmann. Statistical models for granular materials. Physica A, (263):51--62, 1999. [PUMA: Criticality; Granular Heap Ising-Models; Media; Organized Self Shape a of]

H. J. Herrmann, and G. Sauermann. The shape of dunes. Physica A, (283):24--30, 2000. [PUMA: Aeolian Dunes; Granular Shape a heap media; of transport;]

E. Goles, G. González, H. J. Herrmann, and S. Mart\'ınez. Simple lattice model with inertia for sand piles. Granular Matter, 1998. [PUMA: Cellular Heap automata, formation]

A. Coniglio, and H. J. Herrmann. Phase Transitions in Granular Packings. Physica A, (225):1--6, 1996. [PUMA: Frustrated Gas Heap Lattice Percolation Simulations Slope Tail Theory]