Simanungkalit, Benny Agus. “Microcontroller-Based Vehicle Parking Automation Design AT89S51”. Journal of Science Technology (JoSTec) 1, no. 1 (December 29, 2019): 8–14. Accessed May 20, 2024. https://ejournal.ipinternasional.com/index.php/jostec/article/view/46.