1. D. Bacon R. Green R. LeSchack H. Quintal Geoid representation from satellite determined coefficients Doc. TR-70S 1970
2. I. Fischer Geoid contours in North America from astrogeodetic deflections, 1927 North American datum 1967
3. I. Fischer A modification of the mercury datum Tech. Rep. 67 53 1968
4. E. M. Gaposchkin K. Lambeck 1969 Smithsonian standard earth (II) Smithson. Astrophys. Observ. Spec. Rep. 315 1970
5. The relation of some geodetic datums to a global geocentric reference system;Lambeck;Bull. Geod.,1971