'This book is an excellent introduction to the field of molecular line astrophysics. Williams and Viti cover the range of astrophysical conditions that can be probed, and the most useful molecules and transitions. The expositions are lucid, and each chapter directs the reader to papers and books for further study, and to websites where up-to-date molecular data are available. Observational Molecular Astronomy will be a valuable guide to both graduate students and researchers.' Bruce T. Draine, Princeton University 'This handbook provides everything needed to understand molecular astrochemistry - it will prove useful to both observers and theorists alike. It covers all of the topics a modern researcher needs to know in order to carry out observations of molecules in space, and then to reduce and analyse those observations. It also explains all aspects of molecular spectroscopy from choosing the correct molecule to observe, to calculating the physical parameters of the object being observed. All environments are discussed, from nearby clouds to distant galaxies. I am sure that this will become the must-have handbook for all researchers in this field, from new graduate students to seasoned veterans.' Derek Ward-Thompson, University of Central Lancashire 'I would recommend that anyone embarking on a career in radio, microwave, or submillimetre astronomy and wondering what to do, why to do it, and how to do it, should own this book … it is a book that will not languish untouched on a bookshelf, but will be eagerly and often returned to and will become well thumbed.' The Observatory