1. Argust P (1998) Biological Trace Element Research 66: 131
2. Garrett DE (1998) Borates, Handbook of Deposits, Processing, Properties, and Use, Academic Press, San Diego
3. Brotherton RJ (1994) In: King RB (ed), Encyclopedia of Inorganic Chemistry. John Wiley & Sons, Chichester, 1: 374
4. Schubert DM (1993) Boron Compounds-Boron Hydrides, Heteroboranes and Their Metalla Derivatives. In: Kirk-Othmer Encyclopedia of Chemical Technology, 4th Edn, John Wiley & Sons, New York and 5th Edn (2002) published on-line
5. A notable exception is the icosahedral “aromatic” cluster [B12(OH)12]2- and related compounds which contain twelve equivalent B-O bonds, see Maderna A, Knobler CB, Hawthorne MF (2001) Angew Chem Int Ed 40: 9