Tambichik, Muhammad Afiq, Abdul Aziz Abdul Samad, Noridah Mohamad, Ahmad Zurisman Mohd Ali, Md Azree Othuman Mydin, Mohamad Zulhairi Mohd Bosro, and Muhamad Afif Iman. “Effect of Combining Palm Oil Fuel Ash (POFA) and Rice Husk Ash (RHA) As Pozzolan to the Compressive Strength of Concrete”. International Journal of Integrated Engineering 10, no. 8 (December 29, 2018). Accessed August 14, 2020. https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/3077.