Md. Zain, Z., Harun, N., Hanipah, N.N. and Md. Zain, N. 2017. Backstepping and Sliding-Mode Methods for Stabilizing an Underactuated X4-AUV. Journal of Telecommunication, Electronic and Computer Engineering (JTEC). 9, 2-3 (Jun. 2017), 1–7.