1. Editorial

   • A. Held

   EditorialNotes Pages: 675 - 675

2. Plane waves in gauge theories of gravitation

   • W. Adamowicz

   Research Articles Pages: 677 - 691

3. A review of the geometrical equivalence of metrics in general relativity

   • A. Karlhede

   Research Articles Pages: 693 - 707

4. Perfectly conducting ferrofluid in general relativity

   • M. K. Ray
   • S. Banerji

   Research Articles Pages: 709 - 718

5. Notes on recentU ₄ theories of gravitation

   • R. P. Wallner

   Research Articles Pages: 719 - 732

6. Separation of variables in Einstein spaces. II. No ignorable coordinates

   • Charles P. Boyer

   Research Articles Pages: 733 - 741

7. On the gravitational wave induced oscillations of viscoelastic bodies

   • John G. Papastavridis
   • G. Lianis

   Research Articles Pages: 743 - 766

8. Brinkman's theorem in general relativity and non-Riemannian field theories

   • B. T. McInnes

   Research Articles Pages: 767 - 773