N. H. . Mohamad, A. . Sulaiman, J. . Krishnan, M. N. . Mokhtar, and A. S. . Baharuddin, “Microbubbles Size Distribution at Different Palm Oil Mill Effluent (POME) Temperatures for Oil Recovery Study”, SRJ, vol. 14, no. 2, pp. 89–98, Dec. 2017.