  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.
