An excellent reference text for undergraduates. It seems to me that it exceeds the texts of Kreyszig and Wylie, "Advanced Engineering Mathematics". I especially name two very organized short chapters, that of "Quantum operators", and "Representation theory", really short chapters, but that give enough idea to remember the topics discussed in other places with more extension. Also the very short chapter on "tensors". This book naturally assumes that the subject is already known in other courses, where more details have been studied. but here is the same, faster.