Contains the keyword heteropolyanion

O'Halloran KP, Zhao CC, Ando NS, Schultz AJ, Koetzle TF, Piccoli PM, et al. Revisiting the Polyoxometalate-Based Late-Transition-Metal-Oxo Complexes: The "Oxo Wall" Stands. Inorg Chem. 2012;51:7025-31. Abstract