Book excerpt: This book contains lectures on strongly correlated electron systems presented by eminent physicists. These lectures are up-to-date summaries of relevant subjects in the field of condensed matter physics. Contributions include: BCS theory of nodal superconductors; strongly correlated particle systems and composite operator methods; diagonalization- and numerical renormalization-group-based methods for interacting quantum systems; as well as phenomenological aspects of unconventional superconductivity.