IGY Bulletins: No. 25, No. 26, No. 27
Anonymous · Transactions American Geophysical Union · 1959
The following material was prepared by P. S. Freier, E. P. Ney, and J. R. Winckler, of the School of Physics, University of Minnesota. A more detailed report was published in the Journal of Geophysical Research, June 1959.