1. Adamu, C. I., Nganje, T. N., & Edet, A. (2014). Heavy metal contamination and health risk assessment associated with abandoned barite mines in Cross River State, southeastern Nigeria. Nanotechnology Monitoring Managment, Environmental, https://doi.org/10.1016/j.enmm.2014.11.001.
2. Association of Analytical Communities International. (2002). Method Validation Programs. Gaithersburg, MD, USA: Peer Verified Programs.
3. Akamiwor, I. O., Anosike, E. O., & Egwim, O. (2007). Effect of industrial effluent discharge on microbial properties of the new Calabar River. Scientific Research and Essays, 2(1), 1–5.
4. Aleke, C. G., Okogbue, C. O., Aghamelu, O. P., & Nnaji, N. J. (2016). Hydrogeological potential and qualitative assessment of groundwater from the Ajali Sandstone at Ninth mile area, southeastern Nigeria. Environmental Earth Science, 75, 290. https://doi.org/10.1007/s12665-015-4843-3.
5. Aloa, O., Arojojoye, O., Ogunlaja, O., & Fumuyiwa, A. (2010). Impact assessment of brewery effluent on water quality in Majawe, Ibadan. Southwestern Nigeria. Researcher, 2(5), 21–28.