12758-40-6 3,3'-(Dioxodigermoxanylene) dipropanoic acid 3,3'-(Germanoic anhydride) dipropanoic acid Dipropanoic acid germanium sequioxide NSC267004 Propanoic acid, 3,3'-(1,3-dioxo-1,3-digermoxanediyl)bis- Propanoic acid, 3,3'-[oxybis(oxogermylene)]bis- Propionic acid, 3,3'-(1,3-dioxodigermoxanylene)di-