Evaluation of global gravity field models by using GNSS/leveling data: a case study in Vietnam Thi Hong Tham Bui and Truong Thanh Phi Eur. Phys. J. Plus, 138 10 (2023) 953 Published online: 27 October 2023 DOI: 10.1140/epjp/s13360-023-04576-z