From the book reviews: "The present book developed from the teaching experiences of the author in several honors courses. ... All the topics are motivated very nicely, and there are many exercises, which make the book ideal for a first-year graduate course on the subject. ... The style is concise, always very neat, and proofs are given with full details. Hence, I certainly suggest this nice textbook to anyone interested in the subject, even for self-study." (Fabio Nicola, Mathematical Reviews, July, 2014) "This is a clearly written and attractive textbook using a new concept. ... The book includes numerous examples and more than 270 exercises. ... I warmly recommend this book to all graduate students." (Laszlo Leindler, zbMATH, Vol. 1281, 2014)