One-Pot Efficient Synthesis of 2-Aryl-1-arylmethyl-1H-benzimidazoles and 2,4,5-Triaryl-1H-imidazoles Using Oxalic Acid Catalyst - Kokare, Nagnnath D; Sangshetti, Jaiprakash N; Shinde, Devanand B (Synthesis, 2007)