Truong, Nguyen Ngoc, and Tran Van Nhac. “Determination of the Constant <i>W< i>o< sub> For Local Geoid of Vietnam and it’s Systematic Deviation from the Global Geoid”. <i>Vietnam Journal of Marine Science and Technology</i> 17, no. 4B (December 15, 2017): 138–144. Accessed November 5, 2025. https://cip.vast.vn/jmst/article/view/13001.