Physical Review LettersClassical and Quantum Systems with Time-Dependent Harmonic-Oscillator-Type HamiltoniansHarry R. LewisPublished Mar 27, 1967• 613 citationsPublisherAbstractReceived 28 December 1966DOI:https://doi.org/10.1103/PhysRevLett.18.510©1967 American Physical SocietyDOI10.1103/physrevlett.18.510