Fawad Zahoor, Ameer, et al. “Synthesis and Spectral Investigation (1H and 13C) of Tetradentate Schiff Base Ligands for the Preparation of Post Transition Bimetallic Complexes of Antimicrobial Importance”. Asian Journal of Chemistry, vol. 26, no. 3, Jan. 2014, pp. 841-5, doi:10.14233/ajchem.2014.15834.