"This book is strongly recommended to everyone who wants to get a mathematically rigorous as well as readable presentation of the underlying pseudo-Riemannian manifolds of General Relativity Theory."Zentralblatt MATH"... it is a complete and thorough review of the subject from a consistent point of view. It covers some most important mathematical aspects of Einstein's theory of general relativity. Written by a leading authority on the topic, this monograph is sure to become a standard reference in this field."Mathematical Reviews"The book is a thorough and in depth exposition of its subject written in a consistent way ... This will make it a pleasant read not only for students and researchers in physics but also in mathematics. It is a safe bet that this monograph soon will become a standard reference in the field."Monatshefte fur Mathematik"Overall this book presents a wealth of results on the geometry of four-dimensional space-times in a well organized and carefully presented form. Most of them are perhaps rather technical or specialized but they will certainly be useful, in particular, for workers on exact solutions of Einstein's equations."General Relativity and Gravitation