Citation: Merlino, S.; Pasero, M.; Artioli, G.; Khomyakov, A. P. (1994). Penkvilksite, a new kind of silicate structure: OD character, X-ray single-crystal (1M), and powder Rietveld (2O) refinements of two MDO polytypes Note: polytype 1M Data has been corrected according to the ICSD. American Mineralogist, 79, pp. 1185-1193.