Mahamad, Abd Kadir, Azmi Sidek, and Sharifah Saon. 2019. “Electronic Abacus (e-Abacus) Using FPGA Altera DE2 Board”. International Journal of Integrated Engineering 11 (8): 11-18. https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/2704.