Polarization in Spectral Lines Description of Polarized Radiation Angular Momentum and Racah Algebra Atomic Spectroscopy Quantization of the Electromagnetic Field (Non Relativistic Theory) Interaction of Material Systems with Polarized Radiation (the Classical Approach) Interaction of Material Systems with Polarized Radiation (the Quantum Approach) Statistical Equilibrium Equations and Radiative Transfer Coefficients for Atomic Systems Radiative Transfer for Polarized Radiation Line Formation in a Magnetic Field Non Equilibrium Atomic Physics Astrophysical Applications: Solar Magnetometry Astrophysical Applications: Radiation Anisotropy in Stellar Atmospheres Astrophysical Applications: the Outer Layers of Stellar Atmospheres Astrophysical Applications: Stellar Atmospheres.