1. J. BADEKAS and G. VEIS: 1967. A determination of the Standard Earth scale from simultaneous B-N and laser measurements (unpublished).
2. G. BOMFORD: 1963. Paper presented at XIII General Assembly of the IUGG, Berkeley.
3. Irene FISCHER: 1959: A tentative World Datum from geoidal heights based on the Hough ellipsoid and the Columbus geoid. Journ. Geophys. Res., Vol. 64, pp. 73–85.
4. Irene FISCHER and M. SLUTSKY: 1966. Un estudio del geoide en Sud America. Instituto Pan-americano de Geografia e lustonia, Buenos Aires.
5. L.A. GALE: 1967. Letter to Mr. J. Rolff (Julu 6, 1967).