S. Mujiharjo, B. Sidebang, and D. Darmadi, “PERFORMANCE OF A PIPE SLOW SAND FILTER (SSF-P) WITH DIFFERENCE HYDRAULIC HEADS ON FILTERING POLLUTANTS OF CRUMRUBBER PLANT LIQUID WASTE”, JAGOIND, vol. 2, no. 2, pp. 77–83, Nov. 2012.