Addamo M, Bombieri G, Foresti E, Grillone MD, Volpe M. Assembling process of charged nonanuclear cationic lanthanide(III) clusters assisted by dichromium decacarbonyl hydride. Inorg Chem. 2004 Mar 08;43(5):1603–5. doi: 10.1021/ic034700r. PMID: 14989651.