1. Brennecke J. et al. (1983). “A European astro‐gravimetric geoid.” Reihe B: Angewandtw Geodäsie—Heft Nr. 269. Verlag des Instituts für Angewandte Geodäsie Frankfort FRG.
2. The precise computation of geoid undulation differences with comparison to results obtained from the Global Positioning System
3. Fury R. J. (1984). “Prediction of deflections of the vertical by gravimetric methods.” NOAA Technical Report NOS NGS 28 National Geodetic Information Center NOAA Rockville Md. 25 pp.
4. Fury R. J. (1986). “Geoid height estimation technology development to improve computed orthometric height as a complement to GPS.” Internal report National Geodetic Survey NOAA Rockville Md.
5. Hein G. W. (1985). “Orthometric height determinations using GPS observations and integrated geodesy adjustment model.” NOAA Technical Report NOS 110 NGS 32 . National Geodetic Information Center NOAA Rockville Md. 16 pp.