1. Navigation at the Prime Meridian Revisited;Dillon;Navigation, Journal of the Institute of Navigation,1977
2. Navigation at the Prime Meridian;Gebel;Navigation, Journal of the Institute of Navigation,1971
3. The Second International Geodetic Symposium on Satellite Doppler Positioning, held at the L. B. Johnson Library, University of Texas, January 22-26, 1979. Sponsored by the Defense Mapping Agency. Proceedings will be available from the Defense Mapping Agency Hydrographic/Topographic Center, 6500 Brookes Lane, Washington, D.C., 20315
4. The Royal Society Discussion Meeting on Satellite Doppler Tracking and Its Geodetic Applications, held at the Royal Society on October 10-11, 1978 Proceedings of the conference are to appear in September 1979 in an issue of Philosophical Transactions of the Royal Society.