1. Molecular quadrupole moments
2. Molecular hyperpolarisabilities
3. M. P. Bogaard and B. J. Orr, inMolecular Structure and Properties, edited by A. D. Buckingham (Butterworths, London, 1975), Vol. 2, p. 149;
4. A. D. Buckingham, inIntermolecular Interactions: From Diatomics to Biopolymers, edited by B. Pullman (Wiley, New York, 1978), p. 1.
5. N. Bloembergen,Nonlinear Optics(Benjamin, New York, 1965);