Essang, S., and H. Omoregie. “SYNTHESIS AND CHARACTERIZATION OF MIXED LIGAND Mn(II), Co(II), Ni(II) and Cu(II) COMPLEXES OF SOME HYDRAZONES AND NITROGEN DONOR LIGANDS”. LAUTECH Journal of Engineering and Technology, Vol. 14, no. 1, Apr. 2020, pp. 136-52, https://laujet.com/index.php/laujet/article/view/525.