V. Rajachandrasekhar, C. Hariprasad, V. Venugopala Rao, S. Venkataiah, and P. Dubey, “Synthesis of 9,10-Substituted 3,4,10,10a-Tetrahydro-2H,9H-1-oxa-4a,9-diazaphenanthrenes by Reductive Cyclization Method”, ajc, vol. 26, no. 11, pp. 3161–3165, May 2014.