'In the time-honoured tradition of many books from CUP, An Introduction to General Relativity and Cosmology cannot really be described as an introduction at all. … an excellent high-level textbook that includes a number of topics that are not readily to be found elsewhere. I recommend it very highly for students who have studied General Relativity already (perhaps having read a real 'introductory' book), and who would like to gain a deeper mathematical insight into the subject. … For anyone looking for a thorough mathematical treatment of General Relativity, or for a supplement to existing books, this is highly recommended. It is not a standard text by any means, but I would be surprised if there was anyone who didn't find in it something new, interesting, and enlightening.' The Observatory