1 Physics - Applications and Models -- Multiparavector Subspaces of C?n: Theorems and Applications -- Quaternionic Spin -- Pauli Terms Must Be Absent in the Dirac Equation -- Electron Scattering in the Spacetime Algebra -- 2 Physics - Structures -- Twistor Approach to Relativistic Dynamics and to the Dirac Equation - A Review -- Fiber with Intrinsic Action on a 1 + 1 Dimensional Spacetime -- Dimensionally Democratic Calculus and Principles of Polydimensional Physics -- A Pythagorean Metric in Relativity -- Clifford-Valued Clifforms: A Geometric Language for Dirac Equations -- 3 Geometry and Logic -- The Principle of Duality in Clifford Algebra and Projective Geometry -- Doing Geometric Research with Clifford Algebra -- Clifford Algebra of Quantum Logic -- 4 Mathematics - Deformations -- Hecke Algebra Representations in Ideals Generated by q-Young Clifford Idempotents -- On q-Deformations of Clifford Algebras -- Dirac Operator, Hopf Algebra of Renormalization and Structure of Space-time -- Non-commutative Spaces for Graded Quantum Groups and Graded Clifford Algebras -- 5 Mathematics - Structures -- Clifford Algebras and the Construction of the Basic Spinor and Semi-Spinor Modules -- On the Decomposition of Clifford Algebras of Arbitrary Bilinear Form -- Covariant Derivatives on Minkowski Manifolds -- An Introduction to Pseudotwistors: Spinor Solutions vs. Harmonic Forms and Cohomology Groups -- Ordinary Differential Equation: Symmetries and Last Multiplier -- Universal Similarity Factorization Equalities Over Complex.