Physical Review LettersLiu repliesMario LiuPublished May 21, 2001• 6 citationsPublisherAbstractA Reply to the Comment by A. EngelReceived 5 March 2001DOI:https://doi.org/10.1103/PhysRevLett.86.4979©2001 American Physical SocietyDOI10.1103/physrevlett.86.4979