Citation: Wei, Meilin; Wang, Xiaoxiang; Sun, Jingjing; Duan, Xianying (2013). A 3D POM--MOF composite based on Ni(\I\I) ion and 2,2′-bipyridyl-3,3′-dicarboxylic acid: Crystal structure and proton conductivity. Journal of Solid State Chemistry, 202, pp. 200-206.