This is a bundle of all 50 State Research books and it includes two bonus state resources. One Colorado Reading Packet and one 50 States Fact Book where students list state facts. Each state is also individually listed at AJ Bergs, if you want just one state research book type in your state name and research book AJ Bergs. Some of the research books vary in pages. This bundle is great deal if you would like to have all the state research books.