The book contains the material necessary for certification preparation, however, it could be written better.
The authors, or one of the authors, had difficulty developing phrases and constructing sentences. In some sections of the book, there are sentences that are poorly constructed. After careful reading, you will be able to understand what they are trying to convey in the sentence. The author(s) have weak writing skills that need to be improved. Reading the book would be more enjoyable had an editor corrected some of the archaic sentence constructions.
In short, 'A' for material content, 'D+' for writing.