Citation: Fischer, R. X.; Kahlenberg, V.; Voll, D.; MacKenzie, K. J. D.; Smith, M. E.; Schnetger, B.; Brumsack, H.-J.; Schneider, H. (2008). Crystal structure of synthetic Al4B2O9: A member of the mullite family closely related to boralsilite. American Mineralogist, 93, pp. 918-927.