Citation: Malaman, B.; Ijjaali, M.; Gerardin, R.; Venturini, G.; Gleitzer, C. (1992). Fe7(P2O7)4, a mixed-valence iron diphosphate, the missing link between Fe2P2O7 and Fe3(P2O7)2. European Journal of Solid State and Inorganic Chemistry, 29, pp. 1269-1284.