1. Van Allen, J. A., paper presented at joint meeting of National Academy of Sciences and American Physical Society on May 1, 1958.
2. Van Allen, J. A., Ludwig, G. H., Ray, E. C., and McIlwain, C. E., “Observation of High Intensity Radiation by Satellites 1958 Alpha and Gamma”, I.G.Y. Satellite Report Series No. 3: “Some Preliminary Reports of Experiments in Satellites 1958 Alpha and Gamma”, pp. 73–92 (U.S. Nat. Acad. Sci., 1958).
3. I.G.Y. Bull., Trans. Amer. Geophys. Union, 39, 767 (1958).
4. Van Allen, J. A., Ludwig, G. H., Ray, E. C., and McIlwain, C. E., Jet Propulsion, 28, 588 (1958).
5. Van Allen, J. A., “Radiation Measurements with Lunar Probes”, Mem. Tech. Panel on the Earth Satellite Program of the U.S. National Committee for the International Geophysical Year, May 23, 1958 (unpublished).