We just started Core B here. We have the Sonlight book. I am not impressed with it. The one from Sonlight is very outdated in my opinion. There is also a page on Evolution, which is left out of the reading schedule, but my son still wanted to read that page. He is immature (at 6) and thinks the naked pictures are amusing. This is most definitely not a book I would have bought on my own. I hope the book on amazon is an updated edition! :)