'What I consider very valuable in this book are the many exercises for students and, in particular, the references to software repositories, which help students improving their understanding of tomography and practitioners analyzing their data.... This very readable and inspiring book has brought my knowledge and understanding of this very interesting research field to a higher level. ... this book should be on the shelves of every seismology student and every practitioner of global seismic tomography.' Journal of the Acoustical Society of America