I can only give 1 star for the idea behind the book, but the author should have consulted a wider range of people to get to know the typical "German slang". Words like "abasten" or "abflottieren" really don't exist in the actual German language. If you want to know about German slang, buy a book like "Kauderwelsch: American Slang, das Andere Englisch
" from Annette Linnemann and Renate Georgi-Walsk, where you can see the German expression for American slang, too. Or just ask the people around you in Germany, they will help you for sure. But don't buy this book, it's really not worth it.