1. D. J. G. Ives and G. J. Janz, ?Reference Electrodes ?Theory and Practice?, Academic Press, New York (1961) p. 51.
2. J. A. Christiansen and M. Pourbaix,Compt. Rend. Conf. Union Int. Chim. Pure Appl., 17o Conf�rence, Stockholm (1953) p. 83.
3. R. G. Bates, ?Determination of pH ? Theory and Practice?, 2nd edn., Wiley, New York (1973), pp. 12?14, 38.
4. Ref. D. J. G. Ives and G. J. Janz, ?Reference Electrodes ?Theory and Practice?, Academic Press, New York (1961) pp. 12?14, 26?31.
5. R. M. Hawthorne,J. Chem. Educ. 50 (1973) 282.