Yusuf, K A. “Evaluation of the Three-Stage BCR (European Community Bureau of Reference) Sequential Extraction Procedure to Assess the Potential Mobility and Toxicity of Heavy Metals in Roadside Soils”. Biological Sciences - PJSIR 49, no. 3 (June 26, 2006): 181–188. Accessed July 22, 2024. https://v2.pjsir.org/index.php/biological-sciences/article/view/1146.