1. Gibson, J. Sr., and J. A. Van Allen: 1969, ‘Correlation of X-Ray Radiation (2–12 Å) with Microwave Radiation (10.7 cm) from the Non-Flaring Sun’, University of Iowa Research Report, June 1969 (to be submitted to Astrophys. J.).
2. Van Allen, J. A.: 1967, ‘The Solar X-Ray Flare of July 7, 1966’, J. Geophys. Res.
72, 5903–5911.
3. Van Allen, J. A.: 1968a, ‘Adopted Geometric Obliquity Factors for (G1X)33, (GM2-GM3)33, and (GM3-GM2)33 for Explorer 33 for Solar X-Rays, 2 July 1966 to 27 July 1967’,. University of Iowa Memorandum, 2 July 1968.
4. Van Allen, J. A.: 1968b, ‘Corrected Absolute Flux of the July 7, 1966 Solar X-Ray Flare’, J. Geophys. Res.
73, 6863.
5. Van Allen, J. A.: 1968c, ‘Window Thicknesses and X-Ray Efficiencies of GM Tubes on Mariner V, Explorer 33, and Explorer 35’, University of Iowa Memorandum, 26 July 1968.