1. Cain, J. C., Hendriks, S., Daniels, W. E., Jensen, D. C.: 1964, ?Computation of the Main Geomagnetic Field from Spherical Harmonics Expansion?, Goddard Space Flight Center, X-611-64-316, Oct. 1964.
2. Fougere, Paul F.: 1965, ?Spherical Harmonic Analysis, 2, A New Model From Magnetic Observatory Data for Epoch 1960.0?, J. Geophys. Res. 70, 2171.
3. Hassitt, A.: 1965, ?The Average Effect of the Atmosphere on Trapped Protons?, University of California, San Diego, Space Physics Report 65-4 (to be published in J. Geophys. Res.).
4. Hassitt, A.: 1965, ?The Drift Velocity of Trapped Particles?, J. Geophys. Res. 70, 535?540.
5. Jensen, D. C. and Cain, J. C.: 1962, ?An Interim Geomagnetic Field?, J. Geophys. Res. 67, 3568.