Observation of X-ray sources outside the solar system Riccardo GiacconiHerbert Gursky OriginalPaper Pages: 151 - 175
Effects of electromagnetic perturbations on particles trapped in the radiation belts J. W. Dungey OriginalPaper Pages: 199 - 222
The stellar triangulation with photographic observations A. J. Corpacius OriginalPaper Pages: 236 - 261