1. Cook. A. H., J. Chem. Soc., 1938, 876.
2. Cook, A. H., Jones, D. G., ibid., 1938, 1309.
3. Wilson, J. M., Newcombe, R. J., Denaro, A. R., Rickett, R. M. W., Experiments in Physical Chemistry, Pergamon Press, London, 2nd Edn., 1968.
4. Burstall, F. H., Davies, G. R., Wells, R. A., Discuss. Faraday Soc., 1949, 7, 179.
5. Salmon, J. E., Hale, D. K., Ion Exchange, A Laboratory Manual, Butterworth, London, 1959, p. 120.