B. K. Luyen, REFINING GEOIDAL HEIGHTS COMPUTED BY FULLY-NORMALISED SPHERICAL HARMONICS COEFFICIENTS OF THE EARTH GRAVITATIONAL MODEL EGM2008 BY ADJUSTMENT OF COMBINED GPS/LEVELLING/GEOID NETWORK, Vietnam J. Earth Sci. 36 (2014) 169–174. DOI: https://doi.org/10.15625/0866-7187/36/2/4498.