Physical Review LettersFurther Discussion of a Fundamental Theorem in Quantum OpticsI. R. SenitzkyPublished Apr 4, 1966• 6 citationsPublisherAbstractReceived 21 January 1966DOI:https://doi.org/10.1103/PhysRevLett.16.619©1966 American Physical SocietyDOI10.1103/physrevlett.16.619