Contents: J.P. Boehler: Physical motivation -- J.P. Boehler: Introduction to the invariant formulation of anisotropic constitutive equations -- J.P. Boehler: Representations for isotropic and anisotropic non-polynomial tensor functions -- J.P. Boehler: Anisotropic linear elasticity -- J.P. Boehler: Yielding and failure of transversely isotropic solids -- J.P. Boehler: On a rational formulation of isotropic and anisotropic hardening -- J.P. Boehler: Anisotropic hardening of rolled sheet-steel -- A.J.M. Spencer: Isotropic polynomial invariants and tensor functions -- A.J.M. Spencer: Anisotropic invariants and additional results for invariant and tensor representations -- A.J.M. Spencer: Kinematic constraints, constitutive equations and failure rules for anisotropic materials -- J. Betten: Invariants of fourth-order tensors -- J. Betten: Formulation of anisotropic constitutive equations -- J. Betten: Interpolation methods for tensor functions -- J. Betten: Tensor function theory and classical plastic potential.