1. Carroll, D. G. and Wessells, C. W. 1975. A 1975 Astrogeodetic Geoid for the United States. XVIth General Assembly of the International Union of Geodesy and Geophysics. 1975, Grenoble, France.
2. Levallois, J. J. and Monge, H. 1975. Le Geoide European Version 1975. XVIth General Assembly of the International Union of Geodesy and Geophysics. 1975, Grenoble, France.
3. Annexe D