L. D. Volkova, N. A. Zakarina, G. V. Artyukhina, Yu. G. Kul'evskaya, “Adsorption and Structural Properties of Heteropolyacid-modified Pd/AI<sub>2</sub>O<sub>3</sub> Catalysts: Effects on Hydrogenation Activity”, Mendeleev Commun., 4:3 (1994), 107–108