Otuokere, I. E. ., U. F. . Robert, and K. K. . Igwe. “Synthesis, Characterization and Antibacterial Activities of Cu (II) Complex of Benzylpenicillin”. Nigerian Journal of Pharmaceutical and Applied Science Research, vol. 9, no. 1, Aug. 2020, pp. 31-40, http://mail.nijophasr.net/index.php/nijophasr/article/view/328.