1. The modulation collimator in x-ray astronomy

   • H. Bradt
   • G. Garmire
   • H. Gursky

   OriginalPaper Pages: 471 - 506

2. Optical identification and interpretation of x-ray sources

   • Minoru Oda

   OriginalPaper Pages: 507 - 533

3. Predicted performance of a rotating modulation collimator for locating celestial x-ray sources

   • H. W. Schnopper
   • R. I. Thompson
   • S. Watt

   OriginalPaper Pages: 534 - 542

4. Solar eclipses and ionospheric theory

   • H. Rishbeth

   OriginalPaper Pages: 543 - 554

5. Variation in geomagnetic field

   • Hiroshi Maeda

   OriginalPaper Pages: 555 - 590

6. Book reviews

   • W. de Graaff
   • C. de Jager
   • H. G. van Bueren

   BookReview Pages: 591 - 592