'This book is an invaluable collection of information on the most important and most active areas of research in general relativity... For years to come General Relativity and Gravitation will be an important source of information, serving not only active researchers in this field but also students who want to join their ranks.' Foundations of Physics, 16:8 (1986) '...consists of the invited papers and the reports of the various workshops of GR 10. It is a rich source of information on current research in the four main divisions of the subject: classical relativity, relativistic astrophysics, experimental general relativity, and quantum gravity.' Science, 230 (1985) 'Recommended to everybody interested in this field of (astro)physics.' Solar Physics, 98 (1985)