Laurelta, T.-A., and A. Ernest. “Toxicological Effects of Petroleum Refinery Sludge on the Terrestial Environment Using Bacteria and Earthworm As Bio Indicators”. Journal of Advances in Microbiology, Vol. 20, no. 4, May 2020, pp. 30-40, doi:10.9734/jamb/2020/v20i430234.