A. Mustafa, I. et al. 2010. Complexes of Nickel(II), Copper(II) and Zinc(II) Metal Ions with a Tetrabasic Octadentate Schiff-Base Derived from 3,3´ -Diamino-Benzidine and Salicylaldehyde . Asian Journal of Chemistry. 14, 2 (Mar. 2010), 753–760.