Instruct: Classify Amazon reviews into positive or negative sentiment
Query: This book uses copyrighted material without credit

The author, Stephen Van Dulken, has republished without reference or acknowledgment or prior approval of our substantial research regarding the origins and history of tiddlywinks performed in many prior years by me and Fred Shapiro. He has used our research without any reference or attribution. Our research has been published, with copyrights, on tiddlywinks.org since 1997, and in printed materials before then, also copyrighted, Steve Van Dulken has inappropriately used our copyrighted research in this book without approval or attribution. His use of these materials in this book is not approved or accepted and is in violation of our copyrighted materials.