K. Hutter, Order and Disorder in Granular Materials: Experiment and Theory.- W. G. Gray, Elements of a Systematic Procedure for the Derivation of Macroscale Conservation Equations for Multiphase Flow in Porous Media.- K. Wilmanski, Waves in Porous and Granular Materials.- B. A. Schrefler, Numerical Methods in Theories of Porous Materials.- B. Svendsen, A Statistical Mechanical Formulation of Continuum Fields and Balance Relations for Granular and Other Materials with Internal Degrees of Freedom.