Synthesis of symmetrical and unsymmetrical 1,3,4-oxadiazoles and their interconversion to 1,3,4-thiadiazoles and 1,2,4-triazoles - Venkatapuram Padmavathi; Gali Sudhakar Reddy; Annaji Venkata Nagendra Mohan; Konda Mahesh (ARKIVOC, 2009)