Hodnett, BK., & Delmon, B. (1983). Influence of Cobalt On the Textural, Redox and Catalytic Properties of Stoichiometric Vanadium Phosphate. Applied Catalysis A: General, 6(2), 245-259. https://doi.org/10.1016/0166-9834(83)80268-1 (Original work published 1983)