1. Galster H (1990) pH-Messung. VCH, Weinheim
2. Ives DJG, Janz GJ (1961) Reference electrodes, theory and practice. Academic Press, New York
3. Schwabe K (1976) pH-Meßtechnik. Verlag Theodor Steinkopf, Dresden
4. Thomas JM (1999) J Chem Ed 76: 97
5. Hassel AW, Fushimi K, Seo M (1999) Electrochem Commun 1: 180