Siti Zarina Mohd Muji and Zarina Tukiran, ELECTRICAL & ELECTRONIC ENGINEERING: THEORY AND APPLICATIONS SERIES 2: ULTRASONIC AND APPLICATION. Penerbit UTHM, 2015. Accessed: Aug. 26, 2026. [Online]. Available: https://monograph.uthm.edu.my/index.php/penerbituthm/catalog/book/143