Salam, A. and Akhtar, A. 2003. ?SYNTHESIS OF HETERO-BICYCLIC COMPOUNDS PART-X. FORMATION OF 2H,4H,5H 2,2-DIPHENYL-4, 5-DIOXOPYRIDO [4, 3-d] 1,3 DIOXIN. Biological Sciences - PJSIR. 46, 6 (Dec. 2003), 406–408.