O(d, d)-Symmetry and Ernst Formulation for Einstein-Kalb-Ramond Theory   in Three Dimensions
  The Ernst-like matrix representation of the multidimensional Einstein-Kalb-Ramond theory is developed and the O(d,d)-symmetry is presented in the matrix-valued SL(2,R)-form. The analogy with the Einstein and Einstein-Maxwell-Dilaton-Axion theories is discussed. 
A. Herrera and O. Kechkin