M. Taufiq Zaliran, A. Zafiah M. Rus, S. Kormin, and M. Shafiq M Azahari, “Development and Characterization on sound acoustic at photo-induced polymer foam composited at prolonged ultra-violet exposure”, IJET, vol. 7, no. 4.33, pp. 479–486, Dec. 2018, doi: 10.14419/ijet.v7i4.33.28159.