We have synthesized the three dimeric, sandwich-type tungstogermanates [Cu-3(H2O)(B-beta-GeW9O33-(OH))(B-beta-GeW8O30(OH))](12-) (1), [Co(H2O)(2){Co3-(B-beta-GeW9O33(OH))(B-beta-GeW8O30(OH))}(2)](22-) (2), and [Mn(H2O)(2)(Mn-3(H2O)(B-beta-GeW9O33(OH))(B-beta-GeW8O30)(OH))}(2)](22-) (3). Polyanions 1-3 were fully characterized by single-crystal X-ray diffraction elemental and thermogravimetric analysis, and infrared spectroscopy. The magnetic properties of the three compounds were also studied.