Hafizad , S., and B. H. Besar. “Assessment of Heavy Metals Concentrations in Grouper Fish from Kertih Terminal and Tanjung Sulong Port”. International Journal of Synergy in Engineering and Technology, Vol. 1, no. 1, July 2020, https://www.ijset.tatiuc.edu.my/index.php/ijset/article/view/14.