From the reviews:
"If you ever wondered what the big deal is about spectroscopy or wished you understood it a little better, this book’s for you. Robinson takes a step-by-step approach to spectroscopy, each chapter building on the ones before it. ... The book is a worthy addition to any advanced amateur astronomer’s library." (Michael Bakich, Astronomy, February, 2007)
"In this informative monograph, Robinson (Royal Astronomical Society) explains the basic concepts in terms that a general reader can master. Topics such as the characteristic radiation expected to be emitted by atoms, by ionized gas, and by molecules are addressed using illustrations and word descriptions of the physical processes. ... the interested reader will find this book a stimulating introduction. Summing Up: Recommended. General readers; lower-division undergraduates." (D. E. Hogg, CHOICE, Vol. 44 (11), July, 2007)
"In Spectroscopy: The Key to the Stars, Keith Robinson makes spectroscopy approachable for those who are interested in expanding their observational repertoire. ... Not only is this a good read for any observer thinking of taking up spectroscopy, but it’s also suitable for high school or first-year college students in astronomy and physics." (Carolyn Collins Petersen, Sky & Telescope, Vol. 115 (1), January, 2008)
"This is a small book (160 pages) written for amateur astronomers who use CCD cameras and include spectroscopy as part of their observational program. The main purpose of the book is to describe the physics and the physical processes behind the stellar spectra. ... the topics considered are clearly and concisely described. The amateur astronomers, who are not familiar with physics or who have forgotten the essentials of this science, will read it ... with interest and pleasure." (Emile Biemont, Physicalia Magazine, Vol. 29 (4), 2007)