R, Kannamma, Bhargavi S, Bhavani Sree S, and Mahalakshmi J. “Security System to Prevent Tailgating Using Face Recognition and Ultrasonic Sensor”. International Research Journal of Multidisciplinary Technovation 2, no. 5 (September 25, 2020): 20–25. Accessed April 27, 2026. https://journals.asianresassoc.org/index.php/irjmt/article/view/327.