Progress of Theoretical PhysicsQuantum-Statistical Mechanics of Electron-Phonon SystemTakeo MatsubaraPublished Jun 1, 1955• 5 citationsPublisherAbstractTakeo Matsubara; Quantum-Statistical Mechanics of Electron-Phonon System, Progress of Theoretical Physics, Volume 13, Issue 6, 1 June 1955, Pages 628–630, httpsDOI10.1143/ptp.13.628