The book wasn't written by Fischer, you can tell by simply the moves and tactics. That doesn't mean the book is bad. I enjoyed this book it brought my rating up on chess websites for sure, but it won't teach you to play like Fischer, that's for sure. If you want a book by Fischer read "My 60 Best Games" written by Bobby Fischer. He just signed his name onto this book for the money.
This review isn't about that though, the title does technically lie but that didn't make the book not helpful. Definitely an easy book to learn from, a weird page format, but definitely a decent if not a good book.