Comment on ``Spin Correlations in the Paramagnetic Phase and Ring   Exchange in LaCuO''
  It is shown that the experiments of A.M. Toader, J. P. Goff, M. Roger, N. Shannon, J. R. Stewart, and M. Enderle, Phys. Rev. Lett. 94, 197202 (2005) do not provide definitive experimental evidence for ring exchange terms in the Hamiltonian of La2CuO4, even though such terms may be present. 
L. Raymond, G. Albinet, A.-M.S. Tremblay