1. Editorial

   • Hans-Jürgen Schmidt

   Editorial Commentary Pages: 3 - 3

2. Projective Invariance and Einstein's Equations

   • Giovanni Giachetta
   • Luigi Mangiarotti

   OriginalPaper Pages: 5 - 18

3. Integration in the GHP Formalism II: An Operator Approach for Spacetimes with Killing Vectors, with Applications to Twisting Type N Spaces

   • S. Brian Edgar
   • Garry Ludwig

   OriginalPaper Pages: 19 - 59

4. Cosmological Models with Variable Cosmological and Gravitational “Constants” and Bulk Viscous Models

   • Arbab I. Arbab

   OriginalPaper Pages: 61 - 74

5. Two-Soliton Solutions of Axially Symmetric Metrics

   • S. Chaudhuri
   • K. C. Das

   OriginalPaper Pages: 75 - 90

6. Some Properties of the Bel and Bel-Robinson Tensors

   • Miguel Á. G. Bonilla
   • José M. M. Senovilla

   OriginalPaper Pages: 91 - 116

7. Gravitational Waves in Matter

   • R. L. Ingraham

   OriginalPaper Pages: 117 - 140