From the reviews:
"This slim and carefully written book is devoted to projective representations of continuous groups targeted to the fundamental symmetry group of nonrelativistic quantum mechanics the Galilei group. The presentation is self-contained and is supplied with necessary background material and the list of relevant references." (Alexandr S. Holevo, Zentralblatt MATH, Vol. 1077, 2006)
"The book is devoted to the study of symmetries in quantum mechanics. The book ends with an appendix which collects the necessary mathematical definitions, facts, and theorems needed in the book. In my opinion, the presentation of the material is of the highest quality. Clarity and mathematical rigor make the understanding easy and they make the reading joyful. The book is very much recommended for graduate students and/or researchers of either physics or mathematics interested in the theory of quantum mechanics." (L. Molnįr, Publicationes Mathematicae Debrecen, Vol. 68 (1-2), 2006)
