1. Editorial

   • C. de Jager

   EditorialNotes Pages: 3 - 3

2. Some results of ionospheric investigations by means of coherent radiowaves emitted by satellites

   • Ja. L. Al'pert

   OriginalPaper Pages: 5 - 34

3. Techniques for the measurement of extra-terrestrial soft x-radiation

   • R. L. F. Boyd

   OriginalPaper Pages: 35 - 90

4. The interpretation of the XUV solar spectrum

   • C. W. Allen

   OriginalPaper Pages: 91 - 122

5. High energy cosmic gamma rays

   • G. Garmire
   • W. L. Kraushaar

   OriginalPaper Pages: 123 - 146