Orowhigo, Atubi Augustus, and Onu Marcelina Ada. “The Effects of Carbon Black on Human Health in Ubeji, Shaguolo and Environs, Delta State, Nigeria”. International Journal of Medical Science and Clinical invention 5, no. 11 (November 30, 2018): 4162-4177. Accessed October 14, 2019. https://valleyinternational.net/index.php/ijmsci/article/view/1586.