S.W, Puasa, Ismail K.N, and Khairi N.A.I. 2018. “Direct Surfactant-Impregnated Activated Carbon for Adsorption of Reactive Blue 4”. International Journal of Engineering & Technology 7 (4.18): 5-8. https://doi.org/10.14419/ijet.v7i4.18.21810.