^Perrin, D. D., ed. (1982) [1969]. Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution. IUPAC Chemical Data (2nd ed.). Oxford: Pergamon (published 1984). Entry 119. ISBN0-08-029214-3. LCCN82-16524.
^ abHolleman, A.F. (2001). Wiberg, Nils (ed.). Inorganic chemistry (1st English ed.). San Diego, Calif. : Berlin: Academic Press, W. de Gruyter. ISBN0-12-352651-5.