Comments on "Determination of the Nonlinear Optical Susceptibility χ⁽²⁾of Surface Layers" by B. Dick et al.

R.P. Chin, J.Y. Huang, et al.

Physical Review B

M.W. Kim, T.P. Russell, et al.

Macromolecules

Y. Petroff, P.Y. Yu, et al.

Physical Review B

Peter Y. Yu, Y.R. Shen

Physical Review Letters