Rajeswary K, R., N. Abd. Rahman, W. C.S, and A. Bakar N.K. “Effects of Auxiliary Chemicals on the Ozonation of Industrial Dyes”. Malaysian Journal of Science, vol. 24, no. 2, Aug. 2005, pp. 109-16, http://mojes.um.edu.my/index.php/MJS/article/view/8366.