Advanced Book Classics -- Preface -- Preface to the Revised Printing -- Introduction -- The Pairing Theory of Superconductivity -- Applications of the Pairing Theory -- Electron-Ion System -- Field-Theoretic Methods in the Many-Body Problem -- Elementary Excitations in Normal Metals -- Field-Theoretic Methods Applied to Superconductivity -- Electromagnetic Properties of Superconductors -- Conclusion -- Second-Quantization Formalism -- Macroscopic Quantum Phenomena from Pairing in Superconductors -- Microscopic Quantum Interference Effects in the Theory of Superconductivity -- Electron?Phonon Interactions and Superconductivity