Progress of Theoretical PhysicsComments on Biquadratic Exchange Interactions in the Classical Heisenberg ChainB. S. LeePublished Dec 1, 1973• 10 citationsPublisherAbstractB. S. Lee; Comments on Biquadratic Exchange Interactions in the Classical Heisenberg Chain, Progress of Theoretical Physics, Volume 50, Issue 6, 1 December 1973DOI10.1143/ptp.50.2093