1. The world magnetic survey

   • J. P. Heppner

   OriginalPaper Pages: 315 - 354

2. The contribution of observations of satellites to the determination of the Earth's gravitational potential

   • A. H. Cook

   OriginalPaper Pages: 355 - 437

3. Centimeter-wave radio and X-ray emission from the sun

   • M. R. Kundu

   OriginalPaper Pages: 438 - 469