Ho, Richmond Chris Chee Leong, Muhammad Zulkipli, and Muhammad Farid Shaari. “Design of a Low Cost Coin Acceptor for Vending Machine”. Progress in Engineering Application and Technology 2, no. 1 (June 22, 2021): 743–752. Accessed May 6, 2024. https://publisher.uthm.edu.my/periodicals/index.php/peat/article/view/839.