'Immo Appenzeller's text is a complete and comprehensive introduction to the subject. The book covers all relevant aspects of astronomical spectroscopy from the basic physical principles of spectroscopic measurements and their technical implementation in real astronomical instruments to the principles of observations and data reduction. While being guided through the spectroscopic techniques across the electromagnetic spectrum from gamma rays to radio wavelengths, the reader is provided with an insider's overview of today's and future leading astronomical spectroscopic facilities on the ground and in space. The text is a valuable source of information for today's multi-wavelength astronomer who is using a wide range of spectroscopic instruments and is trying to get the best out of the allocated observing time.' Andreas Kaufer, Director, La Silla Paranal Observatory, European Southern Observatory

'This volume is highly recommended for scientists requiring an overview of techniques perhaps outside their main area of research but needing complementary wavelength coverage. It would also be excellent to accompany any course in astronomical techniques.' The Observatory