Ag3PW12O40: A Novel and Recyclable Heteropoly Acid for the Synthesis of 1,5-Benzodiazepines under Solvent-Free Conditions - Yadav, J S; Reddy, B V S; Praveenkumar, S; Nagaiah, K; Lingaiah, N; Saiprasad, P S (Synthesis, 2004)