M. A. Shafii, P. R. Durai, N. M. Rais, and A. A. Latif, “Modification of HMA using palm oil boiler ash as a filler”, IJET, vol. 7, no. 4, pp. 3245–3248, Sep. 2018, doi: 10.14419/ijet.v7i4.21572.